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1.
Int J Biol Macromol ; 273(Pt 2): 133110, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38876230

RESUMO

In food packaging, sodium lignosulfonate nanoparticles (SLS NPs) showed significant antibacterial properties, antioxidant and UV barrier activities. Herein, the SLS NPs were synthesized via a sustainable green method and were added into egg albumin/sodium alginate mixture (EA/SA) to fabricate a safe, edible EA/SA/SNPs food packaging. A composite film EA/SA/SNP was examined microstructurally and physicochemically. The mechanical characteristics, UV protection, water resistance, and the composite film's thermal stability were all enhanced by the inclusion of SLS NPs, and water vapor permeability reduced by 44 %. This composite film exhibited robust antioxidative properties with DPPH and ABTS free radical scavenging rates reaching 76.84 % and 92.56 %, and effective antimicrobial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with antibacterial rates reaching 98.25 % and 97.13 % for the positively charged nanoparticles interacting with the cell membrane. Freshness tests showed that the EA/SA/SNPs packaging film could delay the quality deterioration of fresh tomatoes. This composite film can slow down spoilage bacteria proliferation and prolongs food's preservation period by eight days at ambient temperature.

2.
Int J Biol Macromol ; 270(Pt 1): 132233, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38735617

RESUMO

To reduce food-borne bacterial infection caused by food spoilage, developing highly efficient food packing film is still an urgent need for food preservation. Herein, microwave-assisted antibacterial nanocomposite films CaO2@PVP/EA/CMC-Na (CP/EC) were synthesized using waste eggshell as precursor, egg albumen (EA) and sodium carboxymethylcellulose (CMCNa) as matrix by casting method. The size of CaO2@PVP (CP) nanoparticles with monodisperse spherical structures was 100-240 nm. When microwave and CP nanoparticles (0.05 mg/mL) were treated for 5 min, the mortality of E. coli and S. aureus could reach >97 %. Under microwave irradiation (6 min), the bactericidal rate of 2.5 % CP/EC film against E. coli and S. aureus reached 98.6 % and 97.2 %, respectively. After adding CP nanoparticles, the highest tensile strength (TS) and elongation at break (EB) of CP/EC film reached 19.59 MPa and 583.43 %, respectively. At 18 °C, the proliferation of bacterial colonies on meat can be significantly inhibited by 2.5 % CP/EC film. Detailed characterization showed that the excellent meat preservation activity was due to the synergistic effect of dynamic effect generated by ROS and thermal effect of microwave. This study provides a promising approach for the packaging application of polysaccharide- and protein-based biomass nanocomposite antibacterial edible films.


Assuntos
Antibacterianos , Filmes Comestíveis , Escherichia coli , Conservação de Alimentos , Carne , Micro-Ondas , Polissacarídeos , Staphylococcus aureus , Polissacarídeos/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Conservação de Alimentos/métodos , Carne/microbiologia , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Embalagem de Alimentos/métodos , Animais , Nanocompostos/química , Carboximetilcelulose Sódica/química , Nanopartículas/química , Proteínas/química , Resistência à Tração
3.
Food Chem ; 412: 135554, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36708671

RESUMO

Tetracycline antibiotics (TCs), one of the important antibiotic groups, have been widely used in human and veterinary medicines. Their residues in foodstuff, soil and sewage have caused serious threats to food safety, ecological environment and human health. Here, we reviewed the potential harms of TCs residues to foodstuff, environment and human beings, discussed the luminescence and aptamer sensors based analytical determination, adsorptive removal, and degradation strategies of TCs residues from a recent 5-year period. The advantages and intrinsic limitations of these strategies have been compared and discussed, the potential challenges and opportunities in TCs residues degradation have also been deliberated and explored.


Assuntos
Compostos Heterocíclicos , Poluentes do Solo , Humanos , Luminescência , Antibacterianos/química , Poluentes do Solo/análise , Inocuidade dos Alimentos , Tetraciclinas/análise , Tetraciclina/química
4.
Mater Sci Eng C Mater Biol Appl ; 104: 110000, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499984

RESUMO

Nanomaterials with enzyme-like activity have attracted much attention recently. Herein, we report the synthesis of a new type of 2D MXene-Ti3C2/CuS nanocomposites with peroxidase-like activity using a simple hydrothermal approach. Significantly, compared with the individual MXene-Ti3C2 nanosheets or CuS nanoparticles, the MXene-Ti3C2/CuS nanocomposites show a synergistically enhanced peroxidase-like activity and can be used as an efficient mimetic peroxidase to catalyze the reaction of 3,3,5,5-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2), causing a blue color change. Kinetic studies reveal that the MXene-Ti3C2/CuS nanocomposites have a higher catalytic activity to TMB than their single components, and the catalytic reaction follows the ping-pong mechanism. The MXene-Ti3C2/CuS nanocomposites are used for the colorimetric determination of cholesterol with a linear range of 10-100 µM and a limit of detection (LOD) of 1.9 µM. Our results show that the MXene-Ti3C2/CuS nanocomposites based colorimetric cholesterol biosensor is cost-effective, sensitive, and selective, which has potential application in H2O2 and cholesterol detection and clinic medicine diagnostics.


Assuntos
Colesterol/química , Cobre/química , Nanocompostos/química , Nanopartículas/química , Peroxidase/química , Titânio/química , Benzidinas/química , Técnicas Biossensoriais/métodos , Catálise/efeitos dos fármacos , Colorimetria/métodos , Peróxido de Hidrogênio/química , Cinética , Limite de Detecção , Oxirredução , Peroxidases/química
5.
Mikrochim Acta ; 185(10): 458, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30218157

RESUMO

A composite consisting of graphene oxide and gold nanorods (GO-GNRs) was designed for the trace determination of hepatitis B surface antigen (HBsAg) using surface enhanced Raman spectroscopy (SERS). GO contains numerous carboxy and hydroxy groups on its surface and therefore can serve as the substrate for decoration with GNRs and for immobilizing antibody against HBsAg. The GNRs (carrying the SERS probe 2-mercaptopyridine) exhibit high SERS activity, and this improves the sensitivity of the biosensor. The antibody on the GO-GNRs binds HBsAg with high specificity, and it results in excellent selectivity. The SERS signal (measured at 1002 cm-1) increases in the 1-1000 pg·mL-1 HBsAg concentrations range, and the limit of detection is 0.05 pg·mL-1 (at an S/N ratio of 3). The immunoassay achieves the sensitive and selective determination of HBsAg in serum and expands the potential application of GO-GNR based SERS tag in clinical research. Graphical abstract A novel graphene oxide-gold nanorod (GO-GNRs) based surface-enhanced Raman scattering (SERS) tag for immunoassay was designed. It allows for sensitive and selective determination of HBsAg in serum. The method is expected to expand the potential application in the environment, in medicine and in food analysis.


Assuntos
Ouro/química , Grafite/química , Antígenos de Superfície da Hepatite B/análise , Imunoensaio/métodos , Nanotubos/química , Óxidos/química , Análise Espectral Raman , Humanos , Modelos Moleculares , Conformação Molecular , Propriedades de Superfície
6.
ACS Appl Mater Interfaces ; 10(17): 14342-14355, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29542912

RESUMO

Radiation therapy is a kind of tumor treatment that has been widely employed in clinics, but its therapeutic effect is largely hampered by various factors. Currently, considerable efforts are being made in the search for effective and safe radiosensitizers. A nano-radiosensitizer is an ideal choice for improving the effects of tumor radiotherapy due to its high degree of tumor tissue uptake and secondary electrons' productivity. Herein, highly oxidized graphene quantum dots (GQDs) with a good oxidative stress response and significantly high phototoxicity were prepared and purified via the photo-Fenton reaction of graphene oxide. The enhanced radiosensitization effects were systematically evaluated by monitoring colorectal carcinoma cell cycle and the degree of apoptosis, and the possible mechanism of the GQD irradiating enhancement of cell apoptosis was preliminarily investigated. Our data showed that the GQD synergy with ionizing radiation (IR) could noticeably enhance the G2/M stage arrest of cells, inhibit cell proliferation, and improve apoptosis. This is mainly due to the overproduction of reactive oxygen species by GQDs in combination with the IR, which activates the apoptosis-related regulation proteins and results in tumor cell apoptosis. This study suggests that the GQDs can act as a new nano-radiosensitizer in tumor radiotherapy.


Assuntos
Pontos Quânticos , Apoptose , Grafite , Óxidos , Espécies Reativas de Oxigênio
7.
Mater Sci Eng C Mater Biol Appl ; 82: 197-203, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29025648

RESUMO

The objective of this work was to develop a novel organic-inorganic hybrid nanomaterial from agricultural biomass waste for environmental applications. The sugarcane bagasse (SB) supported TiO2 hybrids were firstly synthesized via a sol-gel method. A series of characterizations were carried out to reveal the structures and components of obtained hybrids. Due to organic-inorganic hybrid (OIH) effect and element doping, the SB-TiO2 hybrid can expand its optical absorbance ranging from ultraviolet to visible light. The optimal hybrid catalyst prepared with SB doping amount of 2g in 100mL titanic gel and calcined at 200°C was able to degradate 95.0% methyl orange (MO) in 5h under visible light. This study will pave a new and facile pathway for novel visible light driven photocatalysts based on TiO2 modified by agricultural biomass waste.


Assuntos
Corantes/química , Luz , Titânio/química , Poluentes Químicos da Água/química , Compostos Azo/química , Biomassa , Catálise , Celulose/química , Géis/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Espectroscopia Fotoeletrônica , Fotólise/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
8.
Mikrochim Acta ; 185(1): 8, 2017 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-29594443

RESUMO

Fluorescent iridium nanoclusters (IrNCs) consisting of up to 7 Ir atoms were prepared by heating IrCl3 in N,N-dimethylformamide. No other reagents are required. High resolution transmission electron microscopy (HRTEM) shows the IrNCs to be monodispersed with an average size of 0.9 ± 0.2 nm. They are well soluble in polar solvents and stable in these solvents for at least 6 months. Under photoexcitation with 365 nm light, they emit strong bluish green fluorescence with peaks that depend on the excitation wavelength and range from 530 to 650 nm. The fluorescence lifetime typically is 2.2 ns and the quantum yield is 8.3%. Fluorescence is quenched by Cr(VI) ion (chromate), and the emission peak is gradually red-shifted. According to the absorbance spectra of IrNCs in the presence and absence of Cr(VI) and Stern-Volmer quenching behavior study, static quenching is involved. Based on these findings, a selective assay was developed for the determination of Cr(VI). It has a linear response in the 0.1 to 100 µM chromate concentration range and a 25 nM detection limit. Graphic abstract Fluorescent iridium nanoclusters (IrNCs), consisting of up to 7 Ir atoms, were prepared in N,N-dimethylformamide (DMF) solution without using any other reagents. Their fluorescence is statically quenched by Cr(VI).

9.
Anal Sci ; 32(7): 725-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27396651

RESUMO

A simple and sensitive surface-enhanced Raman scattering (SERS) method for the detection of ethyl carbamate (EC) is reported in this work. Star-shaped silver nanostars (Ag NSs) were used as a novel SERS substrate. In comparison to other plasmonic nanoparticles (NPs), including Au NPs, Au NSs and Ag NPs, Ag NSs exhibit best SERS activity. Raman signal of EC at a trace level can be enhanced by several orders of magnitude with the help of Ag NSs. The Raman intensity of EC increased linearly with an increase of the EC concentration in the range from 5 × 10(-9) mol L(-1) to 1.0 × 10(-4) mol L(-1) with detection limit (LOD) of 1.37 × 10(-9) mol L(-1) (S/N = 3). The developed SERS approach also has the advantages of being simple, fast and requiring less amount of the sample. It could serve as a useful technology for the rapid determination of EC in both alcoholic beverages and fermented food.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Ouro/química , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Uretana/análise , Vinho/análise , Análise de Alimentos/instrumentação , Limite de Detecção , Tamanho da Partícula , Propriedades de Superfície , Vinho/normas
10.
Talanta ; 117: 425-30, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24209363

RESUMO

A label-free non-aggregation colorimetric sensor has been designed for the detection of Cu(2+), based on Cu(2+) catalyzing etching of gold nanorods (AuNRs) along longitudinal axis induced by dissolve oxygen in the presence of S2O3(2-), which caused the aspect ratio (length/width) of AuNRs to decrease and the color of the solution to distinctly change. The linear range and the detection limit (LD, calculated by 10 Sb/k, n=11) of this sensor were 0.080-4.8 µM Cu(2+) and 0.22 µM Cu(2+), respectively. This sensor has been utilized to detect Cu(2+) in tap water and human serum samples with the results agreeing well with those of inductively coupled plasma-mass spectroscopy (ICP-MS), showing its remarkable practicality. In order to prove the possibility of catalyzing AuNRs non-aggregation colorimetric sensor for the detection of Cu(2+), the morphological structures of AuNRs were characterized by high resolution transmission electron microscopy (HRTEM) and the sensing mechanism of colorimetric sensor for the detection of Cu(2+) was also discussed.


Assuntos
Cobre/análise , Água Potável/química , Ouro/química , Nanotubos/química , Oxigênio/química , Cátions Bivalentes , Cor , Colorimetria/métodos , Humanos , Limite de Detecção , Microscopia Eletrônica de Transmissão , Nanotubos/ultraestrutura , Tiossulfatos/química
11.
Talanta ; 116: 199-204, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24148393

RESUMO

Fe(3+) can catalyze H2O2 to oxidize along on the longitudinal axis of gold nanorods (AuNRs), which caused the aspect ratio of AuNRs to decrease, longitudinal plasmon absorption band (LPAB) of AuNRs to blueshift (Δλ) and the color of the solution to change obviously. Thus, a rapid response and highly sensitive non-aggregation colorimetric sensor for the determination of Fe(3+) has been developed based on the signal amplification effect of catalyzing H2O2 to oxidize AuNRs. This simple and selective sensor with a wide linear range of 0.20-30.00 µM has been utilized to detect Fe(3+) in blood samples, and the results consisted with those obtained by inductively coupled plasma-mass spectroscopy (ICP-MS). Simultaneously, the mechanism of colorimetric sensor for the detection of Fe(3+) was also discussed.


Assuntos
Colorimetria/métodos , Ouro/química , Peróxido de Hidrogênio/química , Ferro/sangue , Absorção , Catálise , Colorimetria/normas , Humanos , Nanotubos/química , Oxirredução , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície
12.
Analyst ; 138(1): 278-83, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23133827

RESUMO

A novel fluorescent probe (Zr(CDs-COO)(2)EDTA) has been designed for fluoride ion (F(-)) content detection based on the competitive ligand reactions carried out between the carboxylate groups (-COOH) on the surface of the luminescent carbon dots (CDs) and F(-) coordinated to Zr(H(2)O)(2)EDTA. The strong and stable fluorescence signal of this probe was quenched upon the addition of F(-) as a result of the formation of the non-fluorescent complex Zr(F)(2)EDTA, due to the stronger affinity of F(-) than the -COOH in the CDs to Zr(IV). The fluorescence change (ΔF) in this process was linear with respect to the content of F(-), ranging from 0.10 µM to 10 µM. The probe has been applied to F(-) detection in toothpaste and water samples with satisfactory results. Moreover, the mechanism of this Zr(H(2)O)(2)EDTA modulated fluorescent probe for the detection of F(-) was also discussed.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Fluoretos/análise , Compostos Organometálicos/química , Zircônio/química , Fluoretos/química , Espectrometria de Fluorescência
13.
Luminescence ; 28(5): 634-40, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23023763

RESUMO

The rhodamine 6G(+) -perphenazine (Rhod 6G(+) -PPH) compound is formed in the ester-exchange reaction between -OH of PPH and -COOC2 H5 of Rhod 6G(+) . PPH was oxidized to a red compound (PPH') in the presence of K2 S2 O8 . Interestingly, the room temperature phosphorescence (RTP) of Rhod 6G(+) was quenched because the -OH of PPH' reacted with -COOC2 H5 of Rhod 6G(+) -PPH to form Rhod 6G(+) -PPH' and PPH, which decreased the π-electron density (δ) of the carbon atom in the Rhod 6G(+) -PPH' conjugated system and enhanced the nonradiation energy loss of the excited Rhod 6G(+) of the triplet state. The PPH content was directly proportional to the ΔIp of the system. Thus, a new catalytic solid-substrate room temperature phosphorimetry (SSRTP) method was established for the determination of PPH. The method had high sensitivity (the limit of detection was 0.019 fg/spot, corresponding to a concentration of 4.8 × 10(-14) g/mL; the sampling quantity was 0.40 µL/spot), good selectivity, convenience and speed. The analytical results were in accordance with those of high-performance liquid chromatography (HPLC). The structures of Rhod 6G(+) , PPH and Rhod 6G(+) -PPH were characterized by infrared spectra. The reaction mechanism by which PPH was determined is discussed.


Assuntos
Medições Luminescentes/métodos , Perfenazina/análise , Rodaminas/química , Temperatura , Catálise , Elétrons , Estrutura Molecular
14.
Artigo em Inglês | MEDLINE | ID: mdl-23201567

RESUMO

ß-CD-HMTA-L-Tyr complex, formed in the host guest inclusion reaction carried out between host molecule ß-cyclodextrin (ß-CD) in ß-CD-HMTA (HMTA is methenamine) and guest molecule L-tryptophan (L-Tyr), possessing the characteristic of room temperature phosphorescence (RTP). Bovine serum albumin (BSA) reacted with L-Tyr to form a complex of cage structure bringing in the sharply RTP signal quenching of L-Tyr. Based on the above facts, a new ultra-sensitive solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace protein has been established using ß-CD-HMTA-L-Tyr complex as a phosphorescence probe. Under the optimum conditions, the linear range of this method was 0.0040-0.56 agspot(-1) with a detection limit (D.L.) as 0.92 zgspot(-1), and the regression equations of working curve was ΔI(p)=0.8239+162.5 m(BSA) (agspot(-1), n=8) with the correlation coefficient (r) of 0.9994. The relatively standard deviation (RSD) and the recovery of SSRTP were 4.8-3.3% and 96.7-102%, respectively, indicating that this method had good repeatability. The proposed phosphorescence probe has been applied in the detection of protein in real samples and the results agreed well with those obtained with SSRTP using methylene blue-sodium tetraphenylborate as phosphorescence probe. Meanwhile, the reaction mechanism for the determination of trace protein with ß-CD-HMTA-L-Tyr complex as phosphorescence probe has been discussed.


Assuntos
Substâncias Luminescentes/química , Metenamina/química , Soroalbumina Bovina/análise , Triptofano/química , beta-Ciclodextrinas/química , Animais , Bovinos , Limite de Detecção , Medições Luminescentes
15.
Analyst ; 137(22): 5346-51, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23033064

RESUMO

Gold nanoclusters (AuNCs) were synthesized by a macromolecules template using bovine serum albumin (BSA) as stabilizer which can emit red photoluminescence under illumination of ultraviolet light. The fluorescence intensity of AuNCs enhanced through decreasing the surface defects of AuNCs modified with cysteine, herein we present a novel fluorometry for determination of trace cysteine. This method with a wider linear range from 2.0 to 800 nmol mL(-1), higher sensitivity (detection limit was 1.2 nmol mL(-1)) and better selectivity has been utilized to determine cysteine content in real samples, and the results were in a good agreement with those determined by electrochemical biosensor. At the same time, the structures of AuNCs and AuNCs-cysteine were characterized by Fourier-transform infrared spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) and the mechanism of the proposed assay for the detection of cysteine has been discussed.


Assuntos
Cisteína/análise , Fluorometria , Ouro/química , Nanopartículas Metálicas/química , Soroalbumina Bovina/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo
16.
Anal Chim Acta ; 744: 60-7, 2012 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-22935375

RESUMO

The present study proposed a simple sensitive and specific immunoassay for the quantification of calcitonin (CT) in human serum with water-soluble multi-walled carbon nanotubes (MWNTs). The COOH group of MWNTs could react with the NH group of rhodamine S (Rhod.S) molecules to form Rhod.S-MWNTs, which could emit room temperature phosphorescence (RTP) on acetate cellulose membrane (ACM) and react with Tween-80 to form micellar compound. Tween-80-Rhod.S-MWNTs (TRM), as a phosphorescent labelling reagent, could dramatically enhance the RTP signal of the system. The developed TRM phosphorescent reagent was used to label anti-calcitonin antibody (Ab(CT)) to form the TRM-Ab(CT) labelling product, which could take high specific immunoreaction with CT, and the ΔI(p) (= I(p2)-I(p1), I(p2) and I(p1) were the phosphorescence intensity of the test solution and the blank sample, respectively) of the system was linear to the content of CT. Hence, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) was established for the determination of CT in human serum. This sensitive (limit of quantification (LOQ) was 8.0×10(-14) g mL(-1)), accurate, selective and precise method has been applied to determine CT in human serum and predict primary osteoporosis and fractures, with the results in good agreement with those obtained by chemiluminescence immunoassay (CLIA). Simultaneously, the structure of MWNTs was characterized with scanning electron microscopy (SEM) and infrared spectroscopy (IR), and the reaction mechanisms of both labelling Ab(CT) with TRM and SSRTPIA for the determination of trace CT were discussed.


Assuntos
Calcitonina/sangue , Corantes Fluorescentes/química , Nanotubos de Carbono/química , Polissorbatos/química , Rodaminas/química , Anticorpos/imunologia , Reações Antígeno-Anticorpo , Calcitonina/imunologia , Humanos , Solubilidade , Água/química
17.
Talanta ; 98: 137-44, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22939139

RESUMO

The CdS/TiO(2)-fluorescein isothiocyanate (FITC) luminescent nanoparticles (CdS/TiO(2)-FITC) with the particle size of 20 nm have been synthesized by sol-gel method. CdS/TiO(2)-FITC could emit the fluorescence of both FITC and CdS/TiO(2). The fluorescence resonance energy transfer (FRET) occurred between the donor CdS/TiO(2) and the acceptor FITC in the CdS/TiO(2)-FITC. Taking advantages of the excellent characteristics of FRET, a new CdS/TiO(2)-FITC FRET labeling reagent and a CdS/TiO(2)-FITC-wheat germ agglutinin (CdS/TiO(2)-FITC-WGA) fluorescent probe have been developed. The FRET occurring between the donor CdS/TiO(2) and the acceptor FITC in the labelled product CdS/TiO(2)-FITC-WGA-AP, formed in the affinity adsorption reaction between the WGA in this CdS/TiO(2)-FITC-WGA fluorescent probe and alkaline phosphatase (AP), sharply enhanced the fluorescence signal of FITC and quench the fluorescence signal of CdS/TiO(2). Moreover, the ΔF (the change of the fluorescence signal) of FITC and CdS/TiO(2) were proportional to the content of AP, respectively. Thus, a new method that CdS/TiO(2)-fluorescein isothiocyanate nanoparticles for the determination of trace AP based on FRET-affinity adsorption assay has been established. The limit of quantification (LOQ) of the method was 1.3×10(-17) g AP mL(-1) for CdS/TiO(2) and 1.1×10(-17) g AP mL(-1) for FITC, respectively. This sensitive, rapid, high selective and precise method has been applied to the determination of AP in human serum and the prediction of human disease with the results agreed well with enzyme-linked immunosorbent assay (ELISA) in Zhangzhou Municipal Hospital of Fujian Province. Simultaneously, the reaction mechanism for the determination of AP was also discussed.


Assuntos
Fosfatase Alcalina/sangue , Compostos de Cádmio/química , Transferência Ressonante de Energia de Fluorescência/métodos , Nanopartículas/química , Sulfetos/química , Titânio/química , Adsorção , Ensaio de Imunoadsorção Enzimática , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/síntese química , Corantes Fluorescentes , Humanos , Sensibilidade e Especificidade , Espectrometria de Fluorescência , Aglutininas do Germe de Trigo/síntese química
18.
Artigo em Inglês | MEDLINE | ID: mdl-22858611

RESUMO

Rhodamine S could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) in the presence of heavy atom perturber Pb(2+). When Rhodamine S-piperidine solution was dropped on PAM, the red (Rhod.S)(n)-P-SOR (Rhod.S, (Rhod.S)(n), P and SOR refer to alizarin red S, multiple Rhod.S molecules, piperidine and self-ordered ring, respectively) formed on PAM, leading to the enhancement of room temperature phosphorimetry (RTP) intensity (I(p), 117.2) of (Rhod.S)(n)-P-SOR system, which was 2.4 times higher than that without SOR (I(p), 48.1). Wheat germ agglutinin (WGA) was labelled with (Rhod.S)(n)-P-SOR by the -NH- of Rhod.S reacting with the -COOH of WGA to form WGA-(Rhod.S)(n)-P-SOR. The formation of WGA-AP-WGA-(Rhod.S)(n)-P-SOR in the affinity adsorption (AA) reaction carried out between the -COOH of WGA in WGA-(Rhod.S)(n)-P-SOR and the -NH(2) of alkaline phosphatase (AP) caused the RTP intensity (ΔI(p)) of the WGA-AP-WGA-(Rhod.S)(n)-P-SOR system 7.8 times larger than that without (Rhod.S)(n)-P-SOR. Therefore, the coupling technique of SOR and solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace AP has been established. This method possessed good selectivity, high sensitivity (Detection limit (L.D) was 3.4×10(-16)gmL(-1)) and accuracy, and it has been applied to the determination of trace AP in human serum and the forecast of human diseases, and the results agreed well with those obtained by enzyme-linked immunoassay (ELISA). Besides, the mechanism of the coupling technique for the determination of AP was discussed.


Assuntos
Fosfatase Alcalina/sangue , Doença , Medições Luminescentes/métodos , Antraquinonas/química , Antraquinonas/metabolismo , Soluções Tampão , Humanos , Limite de Detecção , Piperidinas/química , Piperidinas/metabolismo , Rodaminas/química , Rodaminas/metabolismo , Solventes , Especificidade por Substrato , Temperatura , Aglutininas do Germe de Trigo/metabolismo
19.
Anal Biochem ; 431(1): 19-29, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22906688

RESUMO

Taking advantage of the cutting effect of the strong oxidation of benzoyl peroxide [(C(6)H(5)CO)(2)O(2)] on the end of multiwall carbon nanotubes (MWNTs) to obtain water-soluble multiwall nanotubes (MWNTs') and the spiking effect of polyacrylamide (PA) on the room temperature phosphorescence (RTP) of MWNTs', a new phosphorescent labeling reagent, MWNTs'-PA, has been developed in this study. The product ß-Ab(HCG)-MWNTs'-PA obtained by MWNTs'-PA labeling human chorionic gonadotropin-ß-subunit three-dimensional core monoclonal antibody (ß-Ab(HCG)) not only could maintain good RTP characteristics of MWNTs' but also could take specific immunoreaction with ß-HCG to form ß-HCG- ß-Ab(HCG)-MWNTs'-PA, resulting in the increase of MWNTs' RTP signal. Thus, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) for the determination of ß-HCG has been established. The limits of detection (LODs) of the new method were 0.021pgspot(-1) for the direct way at 447/615nm (λ(ex)(max)/λ(em)(max)) and 0.016pgspot(-1) for the sandwich way at 447/614nm (λ(ex)(max)/λ(em)(max)). This sensitive, accurate, and precise method was used to determine ß-HCG and diagnose human diseases by the direct way or the sandwich way, with the results coinciding with those obtained by chemiluminescence immunoassay. Meanwhile, the mechanisms of MWNTs' labeling ß-Ab(HCG) and determining ß-HCG are also discussed.


Assuntos
Gonadotropina Coriônica/sangue , Imunoensaio , Substâncias Luminescentes/química , Nanotubos de Carbono/química , Resinas Acrílicas/química , Anticorpos Monoclonais/imunologia , Feminino , Humanos , Concentração de Íons de Hidrogênio , Medições Luminescentes , Oxigênio/química , Gravidez , Temperatura
20.
J Fluoresc ; 22(1): 419-29, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21947608

RESUMO

The labelling reagent CdSe@CdS-QDs-Cys (QDs-Cys) with the grain diameter of 4.5 nm was synthesized by modifying CdSe@CdS quantum dots (QDs) with cysteine (Cys). At the same time, QDs-Cys-Ab(IgE), a phosphorescent quantum dot probe, was developed based on the labelling reaction between -COOH of QDs-Cys and -NH(2) of goat anti human IgE antibody (Ab(IgE)). This probe with excellent biocompatibility and high specificity could not only emit strong and stable room temperature phosphorescence (RTP), but also could carry out specific immunoassay (IA) with immunoglobulin E (IgE), causing the RTP of the system to sharply enhance. Thus, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) for the determination of IgE was established. The limit of quantification (LOQ) of the method was 0.12 fg spot(-1), corresponding concentration was 3.0 × 10(-13) g mL(-1) and sampling quantity was 0.40 µL spot(-1). This highly selective, sensitive and accurate SSRTPIA has been applied to determine IgE in biological samples and diagnose diseases, and the results agreed well with those obtained by enzyme-link immunoassay (ELISA). Meanwhile, the mechanisms of QDs-Cys labelling Ab(IgE) and the determination of IgE by SSRTPIA were also discussed.


Assuntos
Compostos de Cádmio/química , Cisteína/química , Imunoensaio/métodos , Imunoglobulina E/análise , Pontos Quânticos , Compostos de Selênio/química , Sulfetos/química , Temperatura , Calibragem , Corantes Fluorescentes/química , Humanos , Umidade , Imunoglobulina E/sangue , Membranas Artificiais , Oxigênio/química , Espectrometria de Fluorescência , Fatores de Tempo
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