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1.
Anal Chem ; 96(19): 7643-7650, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38708712

RESUMEN

Chemiluminescence (CL), especially commercialized CL immunoassay (CLIA), is normally performed within the eye-visible region of the spectrum by exploiting the electronic-transition-related emission of the molecule luminophore. Herein, dual-stabilizers-capped CdTe nanocrystals (NCs) is employed as a model of nanoparticulated luminophore to finely tune the CL color with superior color purity. Initialized by oxidizing the CdTe NCs with potassium periodate (KIO4), intermediates of the reactive oxygen species (ROS) tend to charge CdTe NCs in both series-connection and parallel-connection routes and dominate the charge-transfer CL of CdTe NCs. The CdTe NCs/KIO4 system can exhibit color-tunable CL with the maximum emission wavelength shifted from 694 nm to 801 nm, and the red-shift span is over 100 nm. Both PL and CL of each of the CdTe NCs are bandgap-engineered; the change in the NCs surface state via CL reaction enables CL of each of the CdTe NCs to be red-shifted for ∼20 nm to PL, while the change in the NCs surface state via labeling CdTe NCs to secondary-antibody (Ab2) enables CL of the CdTe NCs-Ab2 conjugates to be red-shifted for another ∼20 nm to bare CdTe NCs. The CL of CdTe753-Ab2/KIO4 is ∼791 nm, which can perform near-infrared CL immunoassay and semi-automatically determined procalcitonin (PCT) on commercialized in vitro diagnosis (IVD) instruments.


Asunto(s)
Compuestos de Cadmio , Mediciones Luminiscentes , Nanopartículas , Telurio , Telurio/química , Inmunoensayo/métodos , Compuestos de Cadmio/química , Nanopartículas/química , Color , Luminiscencia , Automatización , Humanos
2.
Chemosphere ; 357: 141966, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38614401

RESUMEN

Chromium is widely recognized as a significant pollutant discharged into the environment by various industrial activities. The toxicity of this element is dependent on its oxidation state, making speciation analysis crucial for monitoring the quality of environmental water and assessing the potential risks associated with industrial waste. This study introduces a single-well fluorometric sensor that utilizes orange emissive thioglycolic acid stabilized CdTe quantum dots (TGA-QDs) and blue emissive carbon dots (CDs) to detect and differentiate between various chromium species, such as Cr (III) and Cr (VI) (i.e., CrO42- and Cr2O72-). The variations of fluorescence spectra of the proposed probe upon chromium species addition were analyzed using machine learning techniques such as linear discriminant analysis and partial least squares regression as a classification and multivariate calibration technique, respectively. Linear discriminant analysis (LDA) demonstrated exceptional accuracy in differentiating single-component and bicomponent samples. Additionally, the findings from the partial least squares regression (PLSR) showed that the sensor created has strong linearity within the 1.0-100.0, 1.0-100.0, and 0.1-15 µM range for Cr2O72-, CrO42-, and Cr3+, respectively. Furthermore, appropriate detection limits were successfully achieved, which were 2.6, 2.9, and 0.7 µM for Cr2O72-, CrO42-, and Cr3+, respectively. Ultimately, the successful capability of the sensing platform in the identification and quantification of chromium species in environmental water samples provides innovative insights into general speciation analytics.


Asunto(s)
Cromo , Aprendizaje Automático , Puntos Cuánticos , Contaminantes Químicos del Agua , Cromo/análisis , Cromo/química , Puntos Cuánticos/química , Contaminantes Químicos del Agua/análisis , Análisis de los Mínimos Cuadrados , Colorantes Fluorescentes/química , Análisis Discriminante , Telurio/química , Monitoreo del Ambiente/métodos , Compuestos de Cadmio/química , Espectrometría de Fluorescencia/métodos , Carbono/química
3.
J Hazard Mater ; 470: 134218, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38581878

RESUMEN

The development of high-performance sensors for doxycycline (DOX) detection is necessary because its residue accumulation will cause serious harm to human health and the environment. Here, a novel tri-emission ratiometric fluorescence sensor was proposed by using "post-mixing" strategy of different emissions fluorescence molecularly imprinted polymers with salicylamide as dummy template (DMIPs). BSA was chosen as assistant functional monomer, and also acted as sensitizers for the aggregation-induced emission (AIE) effect of DOX. The blue-emitting carbon dots and the red-emitting CdTe quantum dots were separately introduced into DMIPs as the response signals. Upon DOX recognition within 2 min, blue and red fluorescence of the tri-emission DMIPs sensor were quenched while green fluorescence of DOX was enhanced, resulting in a wide range of color variations observed over bluish violet-rosered-light pink-orange-yellow-green with a detection limit of 0.061 µM. The sensor possessed highly selective recognition and was successfully applied to detect DOX in complicated real samples. Moreover, with the fluorescent color collection and data processing, the smartphone-assisted visual detection of the sensors showed satisfied sensitivity with low detection limit. This work provides great potential applications for rapid and visual detection of antibiotics in complex substrates.


Asunto(s)
Antibacterianos , Compuestos de Cadmio , Doxiciclina , Impresión Molecular , Puntos Cuánticos , Espectrometría de Fluorescencia , Telurio , Doxiciclina/análisis , Doxiciclina/química , Puntos Cuánticos/química , Telurio/química , Antibacterianos/análisis , Compuestos de Cadmio/química , Límite de Detección , Fluorescencia , Carbono/química , Colorantes Fluorescentes/química , Polímeros Impresos Molecularmente/química , Teléfono Inteligente
4.
Anal Chim Acta ; 1304: 342579, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38637044

RESUMEN

Plasmon enhanced fluorescent (PEF) with more "hot spots" play a critical role in signal amplified technology to avoid the intrinsic limitation of fluorophore which ascribed to a strong electromagnetic field at the tip structure. However, application of PEF technique to obtain a highly sensitive analysis of medicine was still at a very early stage. Herein, a simple but versatile Ag nanocubes (Agcubes)-based PEF sensor combined with aptamer (Agcubes@SiO2-QDs-Apt) was proposed for highly sensitive detection of berberine hydrochloride (BH). The distance between the plasma Agcubes and the red-emitted CdTe quantum dots (QDs) were regulated by the thickness of silica spacer. The three-dimensional finite-difference time-domain (3D-FDTD) simulation further revealed that Agcubes have a higher electromagnetic field than Ag nanospheres. Compared with PEF sensor, signal QDs-modified aptamer without Agcubes (QDs-Apt) showed a 10-fold higher detection limit. The linear range and detection limit of the Agcubes@SiO2-QDs-Apt were 0.1-100 µM, 87.3 nM, respectively. Furthermore, the PEF sensor was applied to analysis BH in the berberine hydrochloride tablets, compound berberine tablet and urine with good recoveries of 98.25-102.05%. These results demonstrated that the prepared PEF sensor has great potential for drug quality control and clinical analysis.


Asunto(s)
Aptámeros de Nucleótidos , Berberina , Compuestos de Cadmio , Puntos Cuánticos , Fluorescencia , Puntos Cuánticos/química , Compuestos de Cadmio/química , Dióxido de Silicio , Telurio/química , Espectrometría de Fluorescencia/métodos , Aptámeros de Nucleótidos/química , Límite de Detección
5.
Mikrochim Acta ; 191(4): 216, 2024 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-38517549

RESUMEN

A photoelectrochemical (PEC) sensor for the sensitive detection of thrombin (TB) was established. Co-sensitized combination of TiO2 nanoparticles combined with modified cadmium sulfide and cadmium telluride quantum dots (CdS/CdTe QDs) was utilized as a photoactive material. Successful growth of CdS/CdTe quantum dots on mesoporous TiO2 films occured by successive ion-layer adsorption and reaction. This interesting formation of co-sensitive structure is conducive to enhancing the photocurrent response by improving the use rate of light energy. Additionally, the step-level structure of CdS/CdTe QDs and TiO2 NPs shows a wide range of visible light absorption, facilitating the dissociation of excitons into free electrons and holes. Consequently, the photoelectric response of the PEC analysis platform is significantly enhanced. This constructed PEC aptasensor shows good detection of thrombin with a low detection limit (0.033 pM) and a wide linear range (0.0001-100 nM) in diluted actual human serum samples. In addition, this PEC aptasensor also has the characteristics of good stability and good reproducibility, which provides a novel insight for the quantitative measurement of other similar analytes.


Asunto(s)
Compuestos de Cadmio , Nanopartículas , Puntos Cuánticos , Humanos , Puntos Cuánticos/química , Compuestos de Cadmio/química , Telurio/química , Trombina , Reproducibilidad de los Resultados , Técnicas Electroquímicas , Nanopartículas/química
6.
Food Chem ; 445: 138668, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38367555

RESUMEN

Zilpaterol hydrochloride (zilpaterol) is used in animal feed as it can increase the lean meat mass. However, consuming zilpaterol-containing animal products may damage human health. Therefore, rapid detection of zilpaterol is attracting increasing research attention. This study aimed to developed a fast, accurate, and ultrasensitive fluorescence immunoassay based on CdTe quantum dots (QDs). A CdTe QD fluorescence sensor was synthesized from thioglycolic acid using a simple hydrothermal method. The morphology and structure of the CdTe QDs were characterized using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The detection limits of our method in swine urine and pork samples were 0.5 µg/L and 1.2 µg/kg, respectively. A wide linear range of 0.1-10000 µg/L (R2 = 0.996) was achieved. Both within-run precision (CVw) and between-run precision (CVb) were ≤ 10 %. The method was then successfully applied for the analysis of zilpaterol contents in swine urine and pork samples.


Asunto(s)
Compuestos de Cadmio , Carne de Cerdo , Puntos Cuánticos , Carne Roja , Compuestos de Trimetilsililo , Animales , Humanos , Porcinos , Colorantes Fluorescentes/química , Puntos Cuánticos/química , Agua , Compuestos de Cadmio/química , Telurio/química , Espectrometría de Fluorescencia/métodos
7.
Ann Nucl Med ; 38(5): 350-359, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38347280

RESUMEN

PURPOSE: Radiolabeled graphene oxide (GO) nanosheets has been one of the most extensively studied nanoplatform for in vivo radioisotope delivery. Herein, we describe the functionalization of the surface of GO nanosheets with Fe3O4 magnetic nanoparticles, cysteine amino acid as an interface ligand, and cadmium telluride quantum dots. MATERIALS AND METHODS: To enable In vivo PET imaging, the GO@Fe3O4-cys-CdTe QDs were labeled with 68Ga to yield [68Ga] Ga-Go@ Fe3O4-Cys-CdTe QDs. Furthermore, serum stability tests were performed and the biological behavior of the nanocomposite was evaluated in rats bearing fibrosarcoma tumor. RESULTS: Liver, blood and tumor were the most accumulated sites at 1 h after the injection, and the radiolabeled nanocomposite as a PET/MRI imaging agent showed fast depletion from body and acceptable tumor uptake. CONCLUSION: Magnetic (Fe3O4) and fluorescent components (CdTe QDs) along with a positron-emitting radionuclide will help to design a multimodal imaging system (PET/MRI/OI) which will offer the advantages of combined imaging techniques and further possible used in localized radionuclide therapy. Overall, [68Ga] Ga-GO@Fe3O4-cys-CdTe QDs nanocomposite shows great promise as a radiolabeled imaging agent owing to high accumulation in tumor region.


Asunto(s)
Compuestos de Cadmio , Fibrosarcoma , Grafito , Puntos Cuánticos , Ratas , Animales , Compuestos de Cadmio/química , Distribución Tisular , Radioisótopos de Galio/química , Puntos Cuánticos/química , Telurio/química , Tomografía de Emisión de Positrones , Radioisótopos , Fibrosarcoma/diagnóstico por imagen , Imagen Multimodal , Imagen por Resonancia Magnética
8.
Colloids Surf B Biointerfaces ; 235: 113774, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38309154

RESUMEN

This study presents the development of a sensitive and simple enhanced ratiometric fluorescence sensing platform in the consist of CdTe quantum dots (QDs), carbon dots (CDs), and hepatitis B core antibody labeled with horseradish peroxidase (HBcAb-HRP) for the visual analysis of H2O2 and glucose. The sulfur atoms in HBcAb-HRP have a strong affinity for Cd(II), which effectively enhances the fluorescence intensity of the CdTe QDs due to the generation of more radiative centers at the CdTe/Cd-SR complex. In the presence of H2O2, the Cd-S bonds are oxidized to form disulfide products and results in linear fluorescence quenching, while CDs maintain stable. Becasue glucose can be converted into H2O2 with the aid of glucose oxidase, this sensing platform can also be used for analyzing glucose. The detection limits for H2O2 and glucose are 2.9 µmol L-1 with RSD of 2.6% and 1.6 µmol L-1 with RSD of 2.4% respectively. In addition, under UV lamp irradiation, the orange-yellow CdTe QDs gradually quench with increasing H2O2 and glucose, while the blue CDs remain unchanged. A color change from orange-yellow to blue enables a visual semi-quantitative determination of H2O2 in commercial contact lens solution and glucose in human serum without any pretreatment. Thus, this CdTe QDs/CDs ratiometric sensing platform has significant potential for the rapid analysis of H2O2 and glucose in actual application.


Asunto(s)
Compuestos de Cadmio , Puntos Cuánticos , Humanos , Peróxido de Hidrógeno/química , Puntos Cuánticos/química , Glucosa/química , Carbono , Compuestos de Cadmio/química , Telurio/química , Anticuerpos contra la Hepatitis B , Peroxidasa de Rábano Silvestre/química , Colorantes Fluorescentes/química
9.
Food Chem ; 446: 138791, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38422638

RESUMEN

Acid-sensitive CdTe quantum dots-loaded alginate hydrogel (CdTe QDs-AH) beads were designed for the visual detection of SO2 residues. As proof of concept, two types of CdTe QDs were selected as model probes and embedded in AH beads. The entire test was performed within 25 min in a modified double-layer test tube with one bead fixed above the sample solution. Adding citric acid and heating at 70 ℃ for 20 min transformed the sulfites in the solution into SO2 gas, which then quenched the fluorescence of the CdTe QDs-AH beads. Using this assay, qualitative, naked-eye detection of SO2 residues was achieved in the concentration range of 25-300 ppm, as well as precise quantification was possible based on the difference in the average fluorescence brightness of the beads before and after the reaction. Five food types were successfully analysed using this method, which is simpler and more economical than existing methods, and does not require complex pretreatment.


Asunto(s)
Compuestos de Cadmio , Puntos Cuánticos , Puntos Cuánticos/química , Dióxido de Azufre , Compuestos de Cadmio/química , Hidrogeles , Telurio/química , Espectrometría de Fluorescencia/métodos
10.
Food Chem ; 441: 138350, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38183725

RESUMEN

Based on the fluorescence sensor of 3-Mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs), two novel detection methods for aklomide and nitromide were developed. The MPA-CdTe QDs were synthesized and characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), ultraviolet visible (UV-vis) and fluorescence (FL). The quenchings were all static. The binding constants (Ka) at different temperatures were obtained. Electrostatic forces were the main forces for the two bindings. For the detection of aklomide and nitromide, under the optimal conditions, the effects of some metal ions, glucose, bovine serum albumin (BSA) and congeneric drug on the determination were explored. The standard equations were established and the limits of detection (LOD) were 0.0215 and 0.0388 µg mL-1 (3S0/S), repectively. The methods were applied to analyse the samples of chicken and duck, the recoveries were 99.41 % - 101.24 % with RSDs of 0.29 % - 1.19 % (n = 5).


Asunto(s)
Benzamidas , Compuestos de Cadmio , Puntos Cuánticos , Puntos Cuánticos/química , Compuestos de Cadmio/química , Fluorescencia , Telurio/química , Espectrometría de Fluorescencia
11.
Food Chem ; 442: 138458, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38278103

RESUMEN

Malachite green (MG) possesses high toxicity, therefore, the detection of MG in fish tissues is of vital importance. A novel core-shell MIPs doped CdTe quantum dots coated silica nanoparticles (CdTe-MIP/SiO2 NPs) were synthesized via a simple one-pot strategy. The materials were characterized carefully. The resulting CdTe-MIP/SiO2 NPs were coated on the thin layer chromatography plate, and coupled with miniaturized fluorimeter for fluorescence detection of MG in fish samples. The resulting CdTe-MIP/SiO2 NPs based system possessed good linearity (0.01 âˆ¼ 20 µmol/L), high recoveries (98.36 %∼101.45 %) and low detection limit (3.7 nmol/L) for MG. Furthermore, CdTe-MIP/SiO2 NPs based system were employed to measure fish samples spiked with MG, meanwhile, HPLC was utilized to evaluate the accuracy and reliability. And the paired t-test was conducted to evaluate differences between fluorescence method and HPLC, P > 0.05 means no significant difference was observed, the results demonstrated that both fluorescence method and HPLC are suitable for MG analysis.


Asunto(s)
Compuestos de Cadmio , Impresión Molecular , Puntos Cuánticos , Colorantes de Rosanilina , Animales , Polímeros Impresos Molecularmente , Puntos Cuánticos/química , Compuestos de Cadmio/química , Dióxido de Silicio/química , Reproducibilidad de los Resultados , Telurio/química , Impresión Molecular/métodos , Peces , Límite de Detección
12.
Anal Chim Acta ; 1285: 342030, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38057051

RESUMEN

BACKGROUND: As one of the most potent environmental estrogens, 17ß-estradiol (E2), which can be enriched into organisms through the food chain and cause harmful biological effects in humans, has been frequently detected in the water environment of the world. High performance liquid chromatography (HPLC) and gas chromatograohy-mass spectrometry (GC/MS) have been widely used for quantification of E2. Despite excellent accuracy, tedious pretreatment and expensive instruments result in their limited application. It is clear that there is an urgent need to establish simple, sensitive and accurate methods for the determination of E2. RESULTS: A split aptamer-based sandwich-type ratiometric biosensor based on split aptamer was developed by coupling photoelectrochemical and electrochemical assays for E2 detection. For analysis, the two fragments of split aptamer recognized E2 by forming sandwich structure, which triggered hybridization chain reaction (HCR) to produce double-stranded DNA (dsDNA) with CdTe quantum dots (QDs) labeled hairpin DNA. The resultant dsDNA can further absorb methylene blue (MB) to sensitize CdTe QDs for an enlarged photocurrent (IPEC) and output a redox current of IMB, and both of them acted as response signals for detection; [Fe(CN)6]3-/4- probe produced redox current of I[Fe(CN)6]3-/4- as reference signal. Using IMB/I[Fe(CN)6]3-/4- and IPEC/I[Fe(CN)6]3-/4- as yardsticks, the developed split aptamer-based sandwich-type ratiometric biosensor provides two linear ranges of 0.1-5000 pg mL-1 for IMB/I[Fe(CN)6]3-/4- and 0.1-10000 pg mL-1 for IPEC/I[Fe(CN)6]3-/4- with detection limits of 0.06 pg mL-1 and 0.02 pg mL-1, respectively. SIGNIFICANCE: These results of the biosensor are benefiting from the coupling of photoelectrochemical (PEC) and electrochemical (EC) assays as well as the unique cooperative recognition mechanism of split aptamer. This method not only enabled the biosensor to be successfully applied to the determination of E2 in lake water, but also broadens the prospects for the realization of sensitive and accurate detection of E2.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Humanos , Compuestos de Cadmio/química , Puntos Cuánticos/química , Telurio/química , Técnicas Biosensibles/métodos , ADN , Aptámeros de Nucleótidos/química , Estradiol/análisis , Agua , Técnicas Electroquímicas/métodos , Límite de Detección , Oro/química
13.
ACS Sens ; 9(1): 433-443, 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38097397

RESUMEN

Given that intricate toxicological profiles exist among different antibiotics and pose serious threats to the environment and human health, synchronous analysis of multiple residues becomes crucial. Sensor arrays show potential to achieve the above purpose, but it is challenging to develop easy-to-use and high-sensitivity tools because the state-of-the-art arrays often require more than one recognition unit and are monosignal dependent. Here we exquisitely designed a fluorescent nanoprobe (2-aminoterephthalic acid-anchored CdTe quantum dots with Eu3+ coordination, CdTe-ATPA-Eu3+) featuring triple emissions at the same excitation as the only element to fabricate a luminescent sensor array with ratiometric calculations for identifying multiple antibiotics. By taking tetracycline, chlortetracycline, doxycycline, oxytetracycline, penicillin G, and sulfamethoxazole as models, the six species exhibited distinguishable motivation or/and quenching impacts on the three emissions of CdTe-ATPA-Eu3+, which were employed as indicators to perform the ratiometric logical operation and further combined with pattern recognition analysis for multitarget determination. Evidently, such a design exhibits two advances: (1) with the triple-emission probe as the sole receptor requiring neither internal nor external adjustments, the fabricated array acts as an extremely facile tool for multianalyte detection; (2) the ratiometric calculations offer excellent sensitivity and reliability for high-performance determination. Consequently, accurate identification and quantification of individual antibiotics and their combinations at various levels were verified in both laboratory and practical matrices. Our work provides a new tool for simultaneously detecting multiple antibiotics, and it will inspire the development of advanced sensor arrays for multitarget analysis.


Asunto(s)
Compuestos de Cadmio , Puntos Cuánticos , Humanos , Antibacterianos , Compuestos de Cadmio/química , Puntos Cuánticos/química , Reproducibilidad de los Resultados , Telurio/química , Colorantes Fluorescentes/química
14.
Biosensors (Basel) ; 13(9)2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37754111

RESUMEN

This work reports the development and application of a highly selective core@shell-based quantum dot-molecularly imprinted polymer (QD@MIP) sensor for the detection of sulfadiazine (SDZ)-an antibiotic which belongs to the sulfonamide family. The synthesis of the smart material or MIP (molecularly imprinted polymer) was carried out by a precipitation method directly on the quantum dot surface, which played the role of a fluorescent probe in the optical sensor. The synthesized polymer was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Fluorescence experiments were performed in order to evaluate the effects of pH, interaction time of the QD@MIP with the analyte and SDZ concentration in different matrices. Under optimized conditions, a linear concentration range of 10.0-60.0 ppm and a limit of detection of 3.33 ppm were obtained. The repeatability and reproducibility of the proposed QD@MIP were evaluated in terms of the RSD, where RSD values of less than 5% were obtained in both tests. Selectivity studies were carried out in the presence of four possible interfering substances with quenching properties, and the signals obtained for these interferents confirmed the excellent selectivity of the proposed sensor; the imprinting factor value obtained for SDZ was 1.64. Finally, the proposed sensor was applied in real animal-based food samples using a spiked concentration of SDZ, where the recovery values obtained were above 90% (experiments were performed in triplicate).


Asunto(s)
Compuestos de Cadmio , Impresión Molecular , Puntos Cuánticos , Animales , Antibacterianos , Polímeros Impresos Molecularmente , Puntos Cuánticos/química , Compuestos de Cadmio/química , Reproducibilidad de los Resultados , Impresión Molecular/métodos , Telurio/química , Sulfanilamida , Sulfadiazina , Límite de Detección
15.
Analyst ; 148(18): 4456-4462, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37560929

RESUMEN

Herein, a multifunctional electrochemiluminescence (ECL) and photoelectrochemical (PEC) biosensor based on exchange of Ag+ with CdTe QDs was developed for dual-mode detection of thrombin. First, CdTe QDs assembled on an electrode displayed superior ECL and PEC signals. At the same time, C-rich hairpin (HP) DNA linked to silicon spheres loaded a large amount of Ag+, and the specific binding of thrombin to an aptamer led to the release of DNA P; then, DNA P interacted with HP DNA to produce numerous Ag+ ions by an enzyme-digestion amplification reaction. Ag+ underwent ion exchange with CdTe QDs to generate AgTe/CdTe QDs, resulting in much reversed PEC and changed ECL signals for dual-mode detection of thrombin. This work takes advantage of outstanding multi-signals of QDs coupled with convenient ion exchange to achieve multi-mode detection of the target, avoiding false positive or false negative signals generated in the traditional detection process, and thus can be used for the rapid detection of various biomolecules in actual samples.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Puntos Cuánticos/química , Trombina , Compuestos de Cadmio/química , Intercambio Iónico , Telurio/química , ADN/química , Mediciones Luminiscentes/métodos , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Límite de Detección
16.
J Hazard Mater ; 458: 131941, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37392644

RESUMEN

A molecularly imprinted polymers (MIPs)-isolated AuNP-enhanced fluorescence sensor, AuNP@MIPs-CdTe QDs, was developed for highly sensitive and selective detection of oxytetracycline (OTC) in aqueous medium. The developed sensor combined the advantages of strong fluorescence signal of metal-enhanced fluorescence (MEF), high selectivity of MIPs, and stability of CdTe QDs. The MIPs shell with specific recognition served as an isolation layer to adjust the distance between AuNP and CdTe QDs to optimize the MEF system. The sensor demonstrated the detection limit as low as 5.22 nM (2.40 µg/L) for a concentration range of 0.1-3.0 µM OTC and good recovery rates of 96.0-103.0% in real water samples. In addition, high specificity recognition for OTC over its analogs was achieved with an imprinting factor of 6.10. Molecular dynamics (MD) simulation was utilized to simulate the polymerization process of MIPs and revealed H-bond formation as the mainly binding sites of APTES and OTC, and finite-difference time-domain (FDTD) analysis was employed to obtain the distribution of electromagnetic field (EM) for AuNP@MIPs-CdTe QDs. The experimental results combined with theoretical analyses not only provided a novel MIP-isolated MEF sensor with excellent detection performance for OTC but also established a theoretical basis for the development of a new generation of sensors.


Asunto(s)
Compuestos de Cadmio , Impresión Molecular , Oxitetraciclina , Puntos Cuánticos , Polímeros Impresos Molecularmente , Impresión Molecular/métodos , Puntos Cuánticos/química , Compuestos de Cadmio/química , Telurio/química , Agua , Límite de Detección
17.
World J Microbiol Biotechnol ; 39(10): 262, 2023 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-37507604

RESUMEN

Tellurium is a super-trace metalloid on Earth. Owing to its excellent physical and chemical properties, it is used in industries such as metallurgy and manufacturing, particularly of semiconductors and - more recently - solar panels. As the global demand for tellurium rises, environmental issues surrounding tellurium have recently aroused concern due to its high toxicity. The amount of tellurium released to the environment is increasing, and microorganisms play an important role in the biogeochemical cycling of environmental tellurium. This review focuses on novel developments on tellurium transformations driven by microbes and includes the following sections: (1) history and applications of tellurium; (2) toxicity of tellurium; (3) microbial detoxification mechanisms against soluble tellurium anions including uptake, efflux and methods of reduction, and reduced ability to cope with oxidation stress or repair damaged DNA; and (4) the characteristics and applications of tellurium nanoparticles (TeNPs) produced by microbes. This review raises the awareness of microorganisms in tellurium biogeochemical cycling and the growing applications for microbial tellurium nanoparticles.


Asunto(s)
Nanopartículas , Oligoelementos , Telurio/química
18.
Biosensors (Basel) ; 13(7)2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37504112

RESUMEN

A photoelectrochemical (PEC) detection platform was built based on the branched rutile/anatase titanium dioxide (RA-TiO2) electrode. Theoretical calculations proved that the type-II band alignment of rutile and anatase could facilitate charge separation in the electrode. The self-generated electric field at the interface of two phases can enhance the electron transfer efficiency of the electrode. Carboxylated CdTe quantum dots (QDs) were applied as signal amplification factors. Without the target DNA presence, the CdTe QDs were riveted to the surface of the electrode by the hairpin probe DNA. The sensitization of CdTe QDs increased the photocurrent of the electrode significantly. When the target DNA was present, the structural changes of the hairpin probe DNA resulted in the failure of the sensitized structure. Benefiting from excellent electrode structure design and CdTe QDs sensitization strategy, the PEC assays could achieve highly sensitive and specific detection of target DNA in the range of 1 fM to 1 nM, with a detection limit of 0.23 fM. The electrode construction method proposed in this article can open a new avenue for the preparation of more efficient PEC sensing devices.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Compuestos de Cadmio/química , Electrones , Puntos Cuánticos/química , Telurio/química , ADN/química , Técnicas Biosensibles/métodos , Electrodos , Técnicas Electroquímicas/métodos , Límite de Detección
19.
Int J Mol Sci ; 24(11)2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37298273

RESUMEN

In this paper, glutathione (GSH)-coated Zn-doped CdTe quantum dots (QDs) with different particle sizes were synthesized using the "reflow method", and the interaction mechanism between the two QDs and lactoferrin (LF) was investigated systemically with different spectroscopic methods. The steady-state fluorescence spectra showed that the LF formed a tight complex with the two QDs through static bursting and that the electrostatic force was the main driving force between the two LF-QDs systems. The complex generation process was found to be spontaneous (ΔG < 0) and accompanied by exothermic and increasing degrees of freedom (ΔH < 0, ΔS > 0) by using the temperature-dependent fluorescence spectroscopy. The critical transfer distance (R0) and donor-acceptor distance (r) of the two LF-QDs systems were obtained based on the fluorescence resonance energy transfer theory. In addition, it was observed that the QDs changed the secondary and tertiary structures of LF, leading to an increase in the hydrophobicity of LF. Further, the nano-effect of orange QDs on LF is much larger than that of green QDs. The above results provide a basis for metal-doped QDs with LF in safe nano-bio applications.


Asunto(s)
Compuestos de Cadmio , Puntos Cuánticos , Lactoferrina , Puntos Cuánticos/química , Compuestos de Cadmio/química , Telurio/química , Espectrometría de Fluorescencia , Zinc/química
20.
Biosens Bioelectron ; 236: 115418, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37279619

RESUMEN

Multiplexed gene assay for simultaneously detecting the multi-targets of nucleic acids is strongly anticipated for the accurate diseases diagnosis and prediction, and all commercial available gene assays for IVD are a kind of single-target assay. Herein, a dual-potential encoded and coreactant-free electrochemiluminescence (ECL) strategy is proposed for the multiplexed gene assay, which can be conveniently carried out by directly oxidizing the same luminescent tag of dual-stabilizers-capped CdTe nanocrystals (NCs). The CdTe NCs linked with sulfhydryl-RNA via Cd-S bond merely exhibits one ECL process around 0.32 V with a narrow triggering-potential-window of 0.35 V, while CdTe NCs linked with amino-RNA via amide linkage solely gives off one ECL process around 0.82 V with a narrow triggering-potential-window of 0.30 V. Multiplexing ECL of both sulfhydryl-RNA-functionalized CdTe NCs and amino-RNA-functionalized CdTe NCs can be utilized to simultaneously detect the open reading frame 1ab (ORF1ab) and the nucleoprotein (N) genes without crosstalk, in which ECL of sulfhydryl-RNA-functionalized CdTe NCs can dynamically determine ORF1ab from 200 aM to 10 fM with a limit of detection (LOD) of 100 aM, while ECL of amino-RNA-functionalized CdTe NCs can linearly detect N gene from 5 fM to 1 pM with a LOD of 2 fM. Post-engineering CdTe NCs with RNA in a labeling-bond engineering way would provide a potential-selective and encoded ECL strategy for multiplexed gene assay with one luminophore.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Compuestos de Cadmio/química , Técnicas Electroquímicas , Mediciones Luminiscentes , Telurio/química , ARN , Límite de Detección
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