title: Ultrasensitive photoelectrochemical immunoassay through tag induced exciton trapping.
abstract: The development of photoelectrochemical (PEC) sensors with novel principles is of significance in realizing sensitive and low-cost detection. This work uses CuO NPs labeled antibody to construct a simple and sensitive sandwich-type immunobiosensor for the detection of protein. The detection signal is produced by dissolving the CuO NPs to release copper ions, which are then added on a quantum dots (QDs) modified F-doped tin oxide to quench the photocurrent of QDs via copper ion-induced formation of exciton trapping. The formed exciton trapping blocks the escape of photoelectron and thus leads to a "signal off" PEC method for sensitive immunoassay. The proposed method shows a detectable range from 0.05 to 500 ng/mL for α-fetoprotein (AFP) with a detection limit (LOD) of 0.038 ng/mL. This work further extends the application of exciton trapping-based PEC biosensing strategy in bioanalysis. The sensitive analytical performance of the designed route implies a promising potential of the PEC sensing in clinical diagnosis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China; School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China. Electronic address: hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D055664:Electrochemical Techniques; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry; D055668:Photochemical Processes; D045663:Quantum Dots / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000906:Antibodies; D019187:Cadmium Compounds; D000509:alpha-Fetoproteins; D003300:Copper; D013691:Tellurium; C028337:cadmium telluride; C030973:cupric oxide
keywords: Exciton trapping; Immunoassay; Photoelectrochemistry; Quantum dots; α-Fetoprotein