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Your search keyword '"Chai, Yaqin"' showing total 274 results
Start Over Author "Chai, Yaqin" Journal analytical chemistry
274 results on '"Chai, Yaqin"'

30. PEDOT/FeOOH/BiVO4Nanohybrids with Excellent Photoelectric Performance Promoted by Photothermal Effects for the Ultrasensitive Detection of MicroRNA-375-3p

Author

Wang, Shuai, Chai, Yaqin, Yuan, Ruo, and Liu, Hongyan

Abstract

Herein, a novel photoactive poly(3,4-ethyl-enedioxythiophene) (PEDOT)/FeOOH/BiVO4nanohybrid with excellent photoelectrochemical (PEC) efficiency was assembled for the construction of an ultrasensitive biosensor for microRNA-375-3p (miRNA-375-3p) detection. In comparison with the traditional FeOOH/BiVO4photoactive composite, the PEDOT/FeOOH/BiVO4nanohybrids exhibited markedly enhanced photocurrent due to the promoted interfacial charge separation by PEDOT, which was used not only as an electron conductor but also as a localized photothermal heater to enhance the photogenerated carrier separation. Based on this PEDOT/FeOOH/BiVO4photoelectrode and an enzyme-free signal amplification strategy including a target-induced catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR), a PEC sensing platform for the detection of miRNA-375-3p was established, achieving a wide linear range from 1 fM to 10 pM with a low detection limit of 0.3 fM. Moreover, this work provides a general photocurrent enhancement strategy for the development of high-performing PEC biosensors for sensitive detection of biomarkers and early disease diagnosis.

Published
2023
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33. Reverse-micelle synthesis of electrochemically encoded quantum dot barcodes: application to electronic coding of a cancer marker

Author

Xiang, Yun, Zhang, Yuyong, Chang, Yue, Chai, Yaqin, Wang, Joseph, and Yuan, Ruo

Subjects
Bar codes -- Chemical properties, Bar codes -- Composition, Bar codes -- Production processes, Bar codes -- Health aspects, Cancer -- Research, Chemical synthesis -- Methods, Electrochemistry -- Research, Quantum chemistry -- Research, Coding theory -- Research, Biological markers -- Properties, Chemistry
Abstract

Reproducible electrochemically encoded quantum dot (QD) barcodes were prepared using the reverse-micelle synthetic approach. The encoding elements, [Zn.sup.2+], [Cd.sup.2+], and [Pb.sup.2+], were confined within a single QD, which eliminates the cumbersome encapsulation process used by other common nanoparticle-based barcode preparation schemes. The distinct voltammetric stripping patterns of [Zn.sup.2+], [Cd.sup.2+] and [Pb.sup.2+] at distinguishable potentials with controllable current intensities offer excellent encoding capability for the prepared electrochemical (EC) QDs. Additionally, the simultaneous modification of the QD barcode surface with organic ligands during the preparation process make them potentially useful in biomedical research. For proof of concept of their application in bioassays, the EC QD barcodes were further employed as tags for an immunoassay of a cancer marker, carcinoembryonic antigen (CEA). The voltammetrlc stripping response of the dissolved bardcode tags was proportional to log[CEA] in the range from 0.01 to 80 ng [mL.sup.-1], with a detection limit of 3.3 pg [mL.sup.-1]. The synthesized EC QD barcodes hold considerable potential in biodetection, encrypted information, and product tracking. 10.1021/ac902335e

Published
2010

35. Ultrasensitive electrochemical immunosensor for clinical immunoassay using thionine-doped magnetic gold nanospheres as labels and horseradish peroxidase as enhancer

Author

Tang, Dianping, Yuan, Ruo, and Chai, Yaqin

Subjects
Nanotechnology -- Usage, Immunoassay -- Methods, Immunoassay -- Technology application, Phenothiazine -- Chemical properties, CEA (Oncology) -- Identification and classification, Technology application, Chemistry
Abstract

A new signal amplification strategy based on thionine (TH)-doped magnetic gold nanospheres as labels and horseradish peroxidase (HRP) as enhancer holds promise to improve the sensitivity and detection limit of the immunoassay for carcinoembryonic antigen (CEA), as a model protein. This immunoassay system was fabricated on a carbon fiber microelectrode (CFME) covered with a well-ordered anti-CEA/protein A/nanogold architecture. The reverse micelle method was initially used for the preparation of TH-doped magnetic gold nanospheres (nanospheres), and the synthesized nanospheres were then labeled on HRP-bound anti-CEA as a secondary antibody (bionanospheres). Sandwich-type protocol was successfully introduced to develop a new high-efficiency electrochemical immunoassay with the labeled bionanospheres toward the reduction of [H.sub.2][O.sub.2]. Under optimized conditions, the linear range of the proposed immunoassay without HRP as enhancer was 1.2-125 ng/mL CEA, whereas the assay sensitivity by using HRP as enhancer could be further increased to 0.01 ng/mL with the linear range from 0.01 to 160 ng/mL CEA. The developed immunoassay method showed good precision, high sensitivity, acceptable stability and reproducibility, and could be used for the detection of real samples with consistent results in comparison with those obtained by the enzyme-linked immunosorbent assay (ELISA) method.

Published
2008

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