title: A sensitive photoelectrochemical biosensor for AFP detection based on ZnO inverse opal electrodes with signal amplification of CdS-QDs.
abstract: In this work, ZnO inverse opals structure (IOs) based photoelectrochemical (PEC) electrode was fabricated for alpha-fetoprotein (AFP) detection. Then, the uniform CdS quantum dots (QDs) were hydrothermally synthesized, which allowed the binding of AFP and glucose oxidase (GOD) on CdS QDs, forming the AFP-CdS-GOD composite. The competitive immunosensor of AFP and the AFP-CdS-GOD composite with anti-AFP antibodies (Ab) immobilized on FTO (fluorine-doped tin oxide) /ZnO IOs electrode was successfully applied to the detection of AFP. GOD could catalyze glucose to produce hydrogen peroxide (H2O2) acting as an electron donor to scavenge photogenerated holes in the valence band of CdS QDs, reducing the recombination of electrons and holes of CdS QDs. Also the effective energy level matching between the conduction bands of CdS QDs and ZnO widened the range of light absorption, allowing for electron injection from excited CdS QDs to ZnO upon visible light irradiation, which enhanced the photocurrent. The results show that the immunosensor of AFP possesses a large linear detection range of 0.1-500 ng/ml with a detection limit of 0.01 ng/ml. It also exhibits excellent anti-interference property and acceptable stability. This work provides a promising method for achieving excellent photoelectrochemical biosensor detection of other proteins.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Ru
authors.initials: R
authors.lastname: Xu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Yandong
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xia
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Tianxiang
authors.initials: T
authors.lastname: Zhang
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China. Electronic address: ldl@jlu.edu.cn.
authors.forename: Dali
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China; The State Key Laboratory of Bioelectronics, Southeast University, 210096 PR China. Electronic address: songhw@jlu.edu.cn.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Song
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008839:Microelectrodes; D010783:Photometry / Q000295:instrumentation*; D045663:Quantum Dots; D012680:Sensitivity and Specificity; D013440:Sulfides / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: C097353:AFP protein, human; D019187:Cadmium Compounds; D013440:Sulfides; D000509:alpha-Fetoproteins; C034939:cadmium sulfide; D015034:Zinc Oxide
keywords: AFP detection; CdS QDs; Photoelectrochemical biosensor; ZnO inverse opals structure