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1.
Curr Med Imaging ; 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38529653

ABSTRACT

OBJECTIVE: This study aimed to investigate whether there is a correlation between quantitative parameters of dual-energy computed tomography (DECT) and the relative expression of HIF-1α in patients with non-small cell lung cancer (NSCLC) to preliminarily explore the value of DECT in evaluating the hypoxia of tumor microenvironment and tumor biological behavior and provide more information for the treatment of NSCLC. METHODS: This retrospective research included 36 patients with pathologically confirmed NSCLC who underwent dual-energy enhanced CT scans. The quantitative parameters of DECT were analyzed, including iodine concentration, water concentration, the CT values corresponding to 40keV, 70keV, 100keV, and 130keV in arterial and venous phases, and the normalized iodine concentration and the slope of the energy spectrum curve were calculated. Postoperative specimens underwent HIF immunohistochemical staining by two pathologists. Spearman correlation analysis was adopted as the statistical methodology. The data were analyzed by SPSS26.0 statistical software. RESULTS: Water concentration (r=0.659, P<0.001 and r= 0.632, P<0.001, the CT values corresponding to 100keV (r=0.645, P<0.001 and r= 0.566, P<0.001) and 130keV (r=0.687, P<0.001 and r= 0.682, P<0.001) in arterial and venous phases, and CT value of 70keV in arterial phase (r=0.457, P=0.005) were positively correlated with HIF-1α expression level. There was no correlation among iodine concentration, standardized iodine concentration, CT value of 40keV, λHU, and HIF-1α expression in arterial and venous levels (P >0.05). CONCLUSION: The quantitative parameters of DECT have a certain correlation with HIF-1α expression in NSCLC. Moreover, it has been demonstrated that DECT can be used to predict hypoxia in tumor tissues and the prognosis of lung cancer patients.

2.
Anal Chim Acta ; 1301: 342467, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38553124

ABSTRACT

Photoelectrochemistry represents a promising technique for bioanalysis, though its application for the detection of Flap endonuclease 1 (FEN1) has not been tapped. Herein, this work reports the exploration of creating oxygen vacancies (Ov) in situ onto the surface of Bi2O2S nanosheets via the attachment of dopamine (DA), which underlies a new anodic PEC sensing strategy for FEN1 detection in label-free, immobilization-free and high-throughput modes. In connection to the target-mediated rolling circle amplification (RCA) reaction for modulating the release of the DA aptamer to capture DA, the detection system showed good performance toward FEN1 analysis with a linear detection range of 0.001-10 U/mL and a detection limit of 1.4 × 10-4 U/mL (S/N = 3). This work features the bioreaction engineered surface vacancy effect of Bi2O2S nanosheets as a PEC sensing strategy, which allows a simple, easy to perform, sensitive and selective method for the detection of FEN1. This sensing strategy might have wide applications in versatile bioasssays, considering the diversity of a variety of biological reactions may produce the DA aptamer.


Subject(s)
Biosensing Techniques , Flap Endonucleases , Oxygen , Biosensing Techniques/methods , Limit of Detection , Electrochemical Techniques/methods
3.
ACS Appl Mater Interfaces ; 16(7): 8518-8526, 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38335724

ABSTRACT

We have witnessed the fast progress of cathodic photoelectrochemistry over the past decades, though its signal transduction tactic still lacks diversity. Exploring new sensing strategies for cathodic photoelectrochemistry is extremely demanding yet hugely challenging. This article puts forward a unique idea to incorporate an enzymatic reaction-invoked surface polarization effect (SPE) on the surface of BiOIO3 to implement an innovative cathodic photoelectrochemical (PEC) bioanalysis. Specifically, the thioredoxin reductase (TrxR)-mediated reaction produced the polar glutathione (GSH), which spontaneously coordinated to the surface of BiOIO3 and induced SPE by forming a polarized electric field, resulting in improved electron (e-) and hole (h+) pair separation efficiency and an enhanced photocurrent output. Correlating this phenomenon with the detection of TrxR exhibited a high performance in terms of sensitivity and selectivity, achieving a linear range of 0.007-0.5 µM and a low detection limit of 2.0 nM (S/N = 3). This study brings refreshing inspiration for the cathodic PEC signal transduction tactic through enzyme-mediated in situ reaction to introduce SPE, which enriches the diversity of available signaling molecules. Moreover, this study unveils the potential of in situ generated SPE for extended and futuristic applications.


Subject(s)
Biosensing Techniques , Thioredoxin-Disulfide Reductase , Electrochemical Techniques/methods , Biosensing Techniques/methods , Electrodes , Electrons , Limit of Detection
4.
J Mater Chem B ; 11(23): 5123-5130, 2023 06 14.
Article in English | MEDLINE | ID: mdl-37221921

ABSTRACT

Cathodic photoelectrochemistry, a research hotspot in state-of-art bioassays, is generally circumscribed by its monotonous signal transduction tactic of photoinduced electron transfer (PET) mechanism, which significantly narrows the scope of its applications. In this study, we reveal the surface oxygen vacancy (VO) formation elicited by the spontaneous coordination of catechol (CA) onto the surface of BiOI nanoplates for the innovative operation of the cathodic PEC signal transduction tactic. The in situ-generated VO functions as a carrier separation center to efficiently promote photocurrent generation. Taking tyrosinase (TYR) and Escherichia coli O157:H7 (E. coli O157:H7) as model targets, the established signal transduction tactic was validated as efficient and sensitive for the detection of the two targets with linear ranges from 1.0 × 10-4 to 1.0 U mL-1 and 5.0 to 1.0 × 106 CFU mL-1, respectively. Low-detection limits of 1.0 × 10-4 U mL-1 and 3.0 CFU mL-1 were achieved for TYR and E. coli O157:H7, respectively. This study opens up a new perspective of in situ generated surface VO on semiconductors, which underlies an innovative PEC signal transduction mechanism with convincing analytical performance. Hopefully, it might encourage more explorations of new methodologies for introducing surface vacancies with exquisite applications.


Subject(s)
Escherichia coli O157 , Semiconductors , Catechols
5.
Analyst ; 148(9): 2092-2099, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37009815

ABSTRACT

The development of efficient methods for the detection of T4 DNA ligase is extremely important for public health. The present work demonstrates the integration of engineerable oxidase nanozyme of LaMnO3.26 nanomaterials for the colorimetric detection of T4 DNA ligase. Specifically, the LaMnO3.26 nanomaterials exhibited oxidase-like activity, oxidizing o-phenylenediamine (OPD), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and 3,3',5,5'-tetramethylbenzidine (TMB) to their corresponding oxidation products, which featured maximum absorption wavelengths at 450, 417 and 650 nm, respectively, while pyrophosphate ion (PPi) caused an obvious decrease in the oxidase-like activity of LaMnO3.26 through its surface coordination with the surface-exposed Mn element and induced aggregation of the nanozyme. Attributed to the PPi regulated oxidase nanozyme activity, LaMnO3.26 served as a colorimetric probe for the quantitative detection of T4 DNA ligase assisted by a hyperbranched amplification reaction for signal amplification. The T4 DNA ligase was detected with a linear range of 4.8 × 10-3 to 6.0 U mL-1, achieving a detection limit of 1.6 × 10-3 U mL-1. The outcome indicated that the developed nanozyme might be extended to a broad range of practical applications.


Subject(s)
Nanostructures , Oxidoreductases , Colorimetry/methods , DNA Ligases , Oxidation-Reduction , Lanthanum/chemistry
6.
Biosens Bioelectron ; 232: 115286, 2023 Jul 15.
Article in English | MEDLINE | ID: mdl-37079991

ABSTRACT

The state-of-art signal transduction mechanism of anodic photoelectrochemistry is constrained to the hole oxidation reaction, which greatly hinders its application for prospective biosensing applications. Herein, we present an innovative strategy for signal transduction by exploiting the in situ formation of surface oxygen vacancies (VOs) on Fe2O3 nanorods (NRs) through the self-coordination of 2,3-dihydroxynaphthalene (2,3-DHN) on their surfaces. The 2,3-DHN was connected with Fe(Ⅲ) on the surface of Fe2O3 NRs vis the formation of the five-membered ring structures accompanied by the generation of VOs. And the generated VOs introduced a new defect energy level for trapping the photogenerated holes, which enhanced the charge separation and realized the enhancement of photocurrent signal. The developed signal transduction strategy was validated by the first photoelectrochemical (PEC) sensing platform for ß-glucoside (ß-Glu) and lipase (LPS), which can catalyze the hydrolysis of 3-hydroxy-2-naphthalenyl-ß-D-glucoside and naphthalene-2,3-diol diacetate, respectively, to produce 2,3-DHN for signal stimuli. The ß-Glu and LPS were detected with linear ranges of 0.01-10.0 U/mL and 0.001-5.0 mg/mL, respectively. Detection limits of 3.3 × 10-3 U/mL and 0.32 µg/mL (S/N = 3) were achieved, for ß-Glu and LPS, respectively. The present study not only provides a new strategy for spontaneous induction of VOs in situ for n-type semiconductors, but also innovates the anodic PEC signal transduction strategy with broadened biosensing applications.


Subject(s)
Biosensing Techniques , Nanotubes , Ferric Compounds , Lipopolysaccharides , Prospective Studies , Glucosides , Lipase , Oxygen
7.
Anal Chim Acta ; 1249: 340959, 2023 Apr 08.
Article in English | MEDLINE | ID: mdl-36868763

ABSTRACT

A new concept to construct photoresponsive nanozyme through the in situ deposition of electron transporting material (ETM) on BiOBr nanoplates was proposed. That was, the spontaneous coordination of ferricyanide ions (i.e., [Fe(CN)6]3-) onto the surface of BiOBr formed electron transporting material (ETM), which efficiently prevented electron-hole recombination and led to efficient enzyme mimicking activity under light stimuli. Moreover, the formation of the photoresponsive nanozyme was regulated by pyrophosphate ions (PPi) due to the competitive coordination of PPi with [Fe(CN)6]3- onto the surface of BiOBr. This phenomenon allowed the construction of an engineerable photoresponsive nanozyme that was coupled with the rolling circle amplification (RCA) reaction to elucidate a novel bioassay for chloramphenicol (CAP, taken as a model analyte). The developed bioassay manifested the merits of label-free, immobilization-free and with efficiently amplified signal. Quantitative analysis of CAP in a wide linear range from 0.05 to 100 nM with the detection limit of 0.015 nM was realized, which endowed the methodology with sufficiently high sensitivity. It is expected to be a powerful signal probe in bioanalytical field by virtue of its switchable and fascinating visible-light-induced enzyme mimicking activity.


Subject(s)
Biological Assay , Chloramphenicol , Diphosphates
8.
Talanta ; 257: 124335, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36821968

ABSTRACT

It is of significance to develop efficient methods for detecting the activity of T4 polynucleotide kinase (T4 PNK) due to its essential role in the modulation of different life activities. In this work, we constructed a novel nanozyme using Kanamycin (KANA) as a trigger for the [Fe(CN)6]3- coordinated Cu2(OH)3NO3 (Cu2(OH)3NO3/[Fe(CN)6]3-) nanorods, and designed an amplified colorimetric method to detect T4 PNK. That was, the free KANA efficiently triggered the peroxidase-like activity of Cu2(OH)3NO3/[Fe(CN)6]3-, while the bound KANA by its aptamer lost the stimulative capability for the nanomaterials. On the basis of the bioreaction regulated generation of the KANA aptamer, a highly sensitive colorimetric assay aided by the rolling circle amplification (RCA) reaction for the detection of T4 PNK was realized. Results showed that this assay can detect T4 PNK from 1.0 × 10-3 to 10.0 U/mL, with a limit of detection (LOD) of 1.42 × 10-4 U/mL. The assay also showed acceptable performance in the detection of T4 PNK in serum samples. In addition to the satisfactory sensitivity and selectivity, the displayed T4 PNK assay also presented merits of operational convenience, without labeling or immobilization process and did not require costly instrument. It is expected that the KANA as a stimulator would have extended biosensing applications by coupling various bioreactions that can produce the KANA aptamer.


Subject(s)
Biosensing Techniques , Polynucleotide 5'-Hydroxyl-Kinase , Polynucleotide 5'-Hydroxyl-Kinase/metabolism , Colorimetry , Bacteriophage T4 , Biosensing Techniques/methods , Limit of Detection , Oligonucleotides , Kanamycin
9.
Nanoscale ; 15(6): 2954-2962, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-36722391

ABSTRACT

This work conveys a new philosophy of surface self-coordination mediated trap remediation for innovative cathodic photoelectrochemical (PEC) signal transduction. Initially, the surface trap states of CuBi2O4 nanopolyhedra resulting from dangling bonds can function as charge carrier recombination centers, which suppress the carrier separation efficiency and result in a low photocurrent output. Particularly, hydrogen peroxide (H2O2) spontaneously interacts with the uncoordinated Cu(II) on the surface of CuBi2O4, enabling efficient elimination of dangling bonds and remedy of trap states, thereby outputting intensified photocurrent readout. Exemplified by Flap endonuclease 1 (FEN1) as a model target, a tetrahedron DNA (THD)-based strand displacement amplification (SDA) was introduced to manipulate the formation of hemin impregnated G-quadruplex (G-quadruplex/hemin) DNAzyme and the resultant catalytic reduction for H2O2. In addition, a highly efficient and ultra-sensitive PEC sensing platform was achieved for FEN1 detection with a wide linear range from 1.0 fM to 100.0 pM and a detection limit of 0.3 fM (S/N = 3). This work not only establishes a new idea of cathodic PEC signal transduction, but also offers an efficient biosensing platform for FEN1.


Subject(s)
Biosensing Techniques , DNA, Catalytic , G-Quadruplexes , Hydrogen Peroxide , Biosensing Techniques/methods , Hemin/chemistry , DNA , DNA, Catalytic/chemistry , Limit of Detection , Electrochemical Techniques/methods
10.
Mikrochim Acta ; 189(11): 419, 2022 10 17.
Article in English | MEDLINE | ID: mdl-36251095

ABSTRACT

A novel strategy is reported to access high-performance nanozymes via the self-coordination of ferrocyanides ([Fe(CN)6]4-) onto the surface of the Cu3BiS3 (CBS) nanorods. Notably, the in situ formed nanozymes had high catalytic activity, good stability, low cost, and easy mass production. The formed nanozyme catalyzed the oxidation of the typical chromogenic substrate of 3,3',5,5'-tetramethylbenzidine (TMB) with a distinctive absorption peak at 652 nm, accompanied by a blue color development. Moreover, the attachment of deoxyribonucleoside 5'-monophosphates (dNMP) beforehand onto the surface of CBS prevented coordination of ferrocyanides and resulted in the tunable formation of the nanozyme, thereby enabling the construction of an exquisite biosensing platform. Taking the aptasensing of chloramphenicol (CAP) as an example, the engineered nanozyme allowed the construction of a homogenous, label-free, and high-performance bioassay in terms of its convenience and high sensitivity. Under the optimal conditions, changes in the absorption intensity at 652 nm for the oxidized TMB provides a good linear correlation with the logarithm of CAP concentrations in the range 0.1 pM to 100 nM, and the limit of detection was 0.033 pM (calculated from 3σ/s). Considering a vast number of bioreactions can be connected to dNMP production, we expect the engineerable nanozyme as a universal signal transduction scaffold for versatile applications in bioassays. Through the attachment of deoxyribonucleoside 5'-monophosphate (dNMP) on the surface of CBS to regulate the generation of self-coordinated nanozyme CBS/BiHCF, a homogeneous, label-free, and high-performance universal aptasensing platform was constructed.


Subject(s)
Ferrocyanides , Nanotubes , Benzidines , Chloramphenicol , Chromogenic Compounds , Deoxyribonucleosides
11.
Article in English | MEDLINE | ID: mdl-35699981

ABSTRACT

A Gram-stain-negative, non-spore-forming and rod-shaped bacterium, designated strain NS-102T, was isolated from herbicide-contaminated soil sampled in Nanjing, PR China, and its taxonomic status was investigated by a polyphasic approach. Cell growth of strain NS-102T occurred at 16-42 °C (optimum, 30 °C), at pH 5.0-8.0 (optimum, pH 6.0) and in the presence of 0-3.5 % (w/v) NaCl (optimum, without addition of NaCl). The 16S rRNA gene sequence of strain NS-102T shows high similarity to that of Agriterribacter humi YJ03T (96.9 % similarity), followed by Terrimonas terrae T16R-129T (93.8 %) and Terrimonas pekingensis QHT (93.6 %). Average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between the draft genomes of strain NS-102T and A. humi YJ03T were 72.5, 69.4 and 18.6%, respectively. The only respiratory quinone was MK-7, and phosphatidylethanolamine and unidentified lipids were the major polar lipids. The major cellular fatty acids of strain NS-102T contained high amounts of iso-C15 : 0 (24.6 %), iso-C17 : 03-OH (24.1 %), iso-C15 : 0 G (16.6 %) and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) (15.6 %). The G+C content of the total DNA was determined to be 40.0 mol%. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus, strain NS-102T represents a novel species of the genus Agriterribacter, for which the name Agriterribacter soli sp. nov. is proposed. The type strain is NS-102T (=CCTCC AB 2017249T=KCTC 62322T).


Subject(s)
Gammaproteobacteria , Herbicides , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Gammaproteobacteria/genetics , Phospholipids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sodium Chloride , Soil , Soil Microbiology
12.
Chem Commun (Camb) ; 58(29): 4651-4654, 2022 Apr 07.
Article in English | MEDLINE | ID: mdl-35319043

ABSTRACT

Surface-hydroxylation-induced polarization (SHIP) was shown to promote the cathodic photoelectrochemical (PEC) communication of bismuth oxyiodide with doxorubicin (Dox) by as much as three orders of magnitude. This SHIP tactic was used to establish a polarization electric field (PEF) that not only negatively shifted the conduction band (CB) edge but also promoted the dynamic migration of photogenerated electrons of BiOI to Dox. The tactic underlies a pioneering way to boost signal transduction, and hence offers fresh opportunities for high-performance bioassays.


Subject(s)
Bismuth , Electrochemical Techniques , Biological Assay , Electrodes , Signal Transduction
13.
Anal Chem ; 93(51): 17119-17126, 2021 12 28.
Article in English | MEDLINE | ID: mdl-34908413

ABSTRACT

Most of the cathodic photoelectrochemical (PEC) bioassays rely on electron accepting molecules for signal stimuli; unfortunately, the performances of which are still undesirable. New signal transduction strategies are still highly expected for the further development of cathodic photoelectrochemistry as a potentially competitive method. This work represents a new concept of invoked cathodic photoelectrochemistry by a spontaneously formed electron transporter for innovative operation of the sensing strategy. Specifically, the hexacyanoferrate(II) in solution easily self-coordinated with CuO nanomaterials and formed electron transporting copper hexacyanoferrate (CuHCF) on the surface, which endowed improved carrier separation for presenting augmented photocurrent readout. Exemplified by the T4 polynucleotide kinase (T4 PNK) and its inhibitors as targets, a homogenous cathodic PEC biosensing platform was achieved with the distinctive merits of label-free, immobilization-free, and split-mode readout. The mechanism revealed here provided a totally different perspective for signal transduction in cathodic photoelectrochemistry. Hopefully, it may stimulate more interests in the design and construction of semiconductor/transporter counterparts for exquisite operation of photocathodic bioanalysis.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Electrodes , Electrons , Signal Transduction
14.
Mikrochim Acta ; 188(12): 426, 2021 11 23.
Article in English | MEDLINE | ID: mdl-34812943

ABSTRACT

Label-free and turn-on DNA-binding protein detection based on the doxorubicin (Dox)-intercalated DNA as a signal stimulator in cathodic photoelectrochemistry is reported. The double-stranded DNA (dsDNA) acted as the matrix accommodating the intercalative Dox and allowed its effective photoelectrochemical (PEC) communication with the PbS quantum dots (QDs) for realizing cathodic photocurrent readout. In the presence of the target of the vascular endothelial growth factor (VEGF), the dsDNA was prevented from being digested by the exonuclease III (Exo III), allowing the anchor of Dox to perform as activation stimuli of the photocurrent. The VEGF can be detected in the linear range from 1.5 pM to 100 nM, with an impressively low detection limit of 0.49 pM. This study hints the prospect of DNA intercalated architectures as innovative signaling transduction elements for wide and versatile cathodic PEC bioassays. Effective signaling molecules that are conducive to probe-related cathodic PEC bioassays using DNA as the recognition or signification elements are scarce but very demanding. Herein, the doxorubicin intercalated in duplex DNA functions as an efficient signal stimulator of PbS-consisted photocathode, and thus hints the versatility of the strategy for various targets through cathodic photoelectrochemistry.


Subject(s)
Biosensing Techniques/methods , DNA/chemistry , Doxorubicin/therapeutic use , Intercalating Agents/chemistry , Lead/chemistry , Photochemistry/methods , Sulfides/chemistry , Doxorubicin/pharmacology , Humans
15.
Anal Chim Acta ; 1182: 338945, 2021 Oct 16.
Article in English | MEDLINE | ID: mdl-34602198

ABSTRACT

Conventionally, the photoelectrochemistry relies on freely diffusive signal molecules in solution to stimulate the photocurrent output, leading to limited sensing strategies. Herein, we showcase the methylene blue (MB) embedded duplex DNA for efficient signal stimuli and its application for ultrasensitive photoelectrochemical (PEC) bioassay. Specifically, the MB embedded duplex DNA scavenged the photogenerated holes of petal-like BiVO4 efficiently, and thus greatly augmented the anodic photocurrent output. Taking the miRNA-21 as a model target, whose biorecognition reaction was aided by the rolling circle amplification (RCA) reaction to finally produce an amplified amount of double-stranded DNA (dsDNA) with embedded MB on the photoelectrode's surface, a "label-free" and "signal-on" PEC biosensing platform was implemented with ultra-sensitivity and high selectivity. The proposed strategy could detect miRNA-21 in the concentration range of 5.0 fM to 10 nM, with the detection limit as low as 0.3 fM. This work opens up the utilization of redox substance intercalated duplex DNA for an efficient signal stimulator, which hints the prospect of other more intercalators embedded DNA for versatile biosensing purposes. Importantly, considering the large quantities of bioreactions that involve duplex DNA as reactants/products, the developed signal transduction strategy may further find wide applications in bioanalysis for targeting more analytes.


Subject(s)
Biosensing Techniques , Methylene Blue , Biological Assay , DNA , Diffusion , Electrochemical Techniques , Intercalating Agents , Limit of Detection
16.
Chem Commun (Camb) ; 57(71): 8989-8992, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34486607

ABSTRACT

We present the in situ formation of a hole-transporting material (bismuth hexacyanoferrate) on the surface of bismuth tungstate aimed at an innovative photoelectrochemical strategy. This approach enabled a competent aptasensing platform for chloramphenicol that was amenable to homogenous, label-free, and split-mode detection.


Subject(s)
Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Bismuth/chemistry , Electrochemical Techniques/methods , Tungsten Compounds/chemistry , Animals , Chloramphenicol/analysis , Chloramphenicol/chemistry , Ferricyanides/chemistry , Food Contamination/analysis , Lakes/analysis , Limit of Detection , Milk/chemistry , Photochemical Processes , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry
17.
Talanta ; 228: 122268, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-33773716

ABSTRACT

Smart nanozymes that can be facile and rapidly produced, while with efficiently bio-regulated activity, are attractive for biosensing applications. Herein, a smart nanozyme, silver hexacyanoferrate (Ag4[Fe(CN)6]), was constructed in situ via the rapid, direct reaction between silver(I) and K4[Fe(CN)6]. And the activity of the nanozyme can be rationally modulated by different enzymatic reactions including the glucose oxidase (GOx, taken as a model oxidoreductase), alkaline phosphatase (ALP), and acetylcholinesterase (AChE). On the basis of which, a multiple function platform for the highly sensitive detection of glucose, ALP and AChE were developed through colorimetry. Corresponding detection limits for the above three targets were found to be as low as 0.32 µM, 3.3 U/L and 0.083 U/L (S/N = 3), respectively. The present study provides a novel nanozyme that can be produced in situ, which rules out the harsh, cumbersome, and time-consuming synthesis/purification procedures. In addition, it establishes a multiple function platform for the amplified detection of versatile targets by the aid of the developed nanozyme, whose detection has the advantages of low cost, ease-of-use, high sensitivity, and good selectivity.


Subject(s)
Biosensing Techniques , Silver , Colorimetry , Ferrocyanides , Glucose Oxidase
18.
Analyst ; 146(8): 2646-2652, 2021 Apr 26.
Article in English | MEDLINE | ID: mdl-33660702

ABSTRACT

In this work, we report the first exploration of cathodic photoelectrochemistry for the determination of the activity of DNA adenine methylation (Dam) methyltransferase (MTase). In this sensing system, potassium ferricyanide (K3[Fe(CN)6]) can greatly stimulate the photocurrent of a CdS quantum dot (QD) sensitized NiO (NiO/CdS) photocathode. After immobilization of the hairpin DNA probe on the electrode surface, its high steric hindrance and the electrostatic repulsion block the access of K3[Fe(CN)6] to the electrode surface, leading to depressed photocurrent of the photocathode. Once the hairpin DNA probe is methylated by Dam MTase, it can be recognized and cleaved by Dpn I, and then further digested by (Exo I), ultimately leading to the removal of the hairpin DNA probe from the electrode surface. This configurational change induces the decrement of steric hindrance/electrostatic repulsion effects and allows the efficient flux of K3[Fe(CN)6] to the photoelectrode for photocurrent stimulation. The cathodic PEC assay is presented in the "turn-on" mode, which can detect Dam MTase in the linear range from 0.04 to 100 U mL-1, with a detection limit as low as 0.028 U mL-1. In principle, the platform presents a promising method for probing various biomolecules that can lead to configuration or charge variations at the electrode surface, which may become a general strategy for versatile targets.


Subject(s)
Biosensing Techniques , DNA Methylation , Adenine , DNA , Electrodes , Site-Specific DNA-Methyltransferase (Adenine-Specific)/metabolism
19.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3267-3272, 2020 Oct.
Article in Chinese | MEDLINE | ID: mdl-33314814

ABSTRACT

To elucidate the composition of semiochemicals of Apriona germari and its function in sexual communication, GC-MS was used to detect the composition of semiochemicals of the overall body and the end abdominal tissue extracts in A. germari. Y-tube olfactometer was used to determine the olfactory response of adult female and male to the standard compounds of the five main extracts. The contact reaction test with male and female adults was performed to the eluted adults that smeared tandard compounds. The results showed that the main ingredients of semiochemicals were alkanes and alkenes with more than 10 carbons. Concentration of (Z)-9-Tricosene was the highest, followed by heptacosane, nonacosane, nonadecene, octacosane, 9-Hexylheptadecane, aldehyde, and ester. Results of the olfactory reaction showed that nonacosane had a significant attractivity to both male and female adults, and that heptacosane had a significant attractivity only to female adults. Nonadecene had a extremely significant repellent activity to female adults. 1-docosene and (Z)-9-Tricosene had no evident role to the male and female adults. Results of the contact test showed that male adults had the strongest courtship responses to the eluted adults with 1-docosene, heptacosane and nonacosane. Female adults had the strongest courtship responses to the eluted adults with nonacosane. Our results indicated that 1-docosene, heptacosane, and nonacosane were important component of the sex pheromone of A. germari, which played an important role in the sexual communication.


Subject(s)
Coleoptera , Sex Attractants , Animals , Communication , Female , Gas Chromatography-Mass Spectrometry , Male
20.
ACS Sens ; 5(12): 3827-3832, 2020 12 24.
Article in English | MEDLINE | ID: mdl-33315371

ABSTRACT

This work presents the concept of establishing interfacial charge-transfer transitions (ICTT) on ferroelectric perovskites for efficient photoelectrochemical (PEC) bioanalysis. The model system was exemplified by using representative lead titanate (PbTiO3) and an enzyme tandem consisting of the isocitrate dehydrogenase (ICDH) and p-hydroxybenzoate hydroxylase (PHBH). The enzymatic generation of protocatechuic acid (PCA) can coordinate onto the surface of the PbTiO3 and hence form the ICTT that enables direct ligand-to-metal charge transfer from the highest occupied molecular orbital (HOMO) of PCA to the conduction band (CB) of PbTiO3 under light irradiation. Due to the ferroelectric polarization induced electric field of PbTiO3 and the surface polarity of PCA modification, enhanced charge separation of the ICTT contributes to the generation of anodic photocurrent and thus underlies a unique route for detecting the enzymatic activity or its substrate. For dehydrogenase detection, this strategy has better performance than some classical methodologies in terms of high sensitivity and improved selectivity. This work not only features ICTT establishment on ferroelectric perovskites for unique bioanalysis but also provides new insights into the utilization of ferroelectric perovskites for advanced PEC bioanalysis.


Subject(s)
Electrochemical Techniques , Oxides , Calcium Compounds , Electrodes , Titanium
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