title: A novel multi-amplification photoelectrochemical immunoassay based on copper(II) enhanced polythiophene sensitized graphitic carbon nitride nanosheet.
abstract: A new sandwich photoelectrochemical (PEC) sensing strategy was proposed for the first time based on the increasing photocurrent of water-soluble polythiophene sensitized g-C3N4 nanosheet (PT-Cl/g-C3N4) in the presence of copper(II) (Cu(2+)), which was doped on the surface of titanium dioxide as labels for multi-amplification. Herein, the photoactive films of PT-Cl/g-C3N4 is employed as the photoactive antibody (Ab1) immobilization matrix for the subsequent sandwich-type antibody-antigen affinity interactions. Upon the presence of antigen (Ag), greatly enhanced photocurrent could be triggered in the PEC platform by the labels of second antibody (Ab2) of Cu(2+) doped titanium dioxide (Cu(2+)-TiO2). As a result of the multi-amplification in this Cu(2+)-TiO2 enhanced PT-Cl/g-C3N4-based PEC immunoassay, it possesses excellent analytical performance. The antigen could be detected from 0.01 pg mL(-1) to 100.0 ng mL(-1) with a detection limit of 5 fg mL(-1). This work opens up g-C3N4 nanosheet applied in PEC sensing. More importantly, the strategy of specific positive effect of Cu(2+) on the photocurrent of g-C3N4 opens an alternative horizon for PEC sensing.
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China.
authors.forename: Rongxia
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China. Electronic address: dubin61@gmail.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D003300:Copper; D055664:Electrochemical Techniques; D006108:Graphite; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry; D009570:Nitriles; D009687:Nuclear Proteins / Q000032:analysis; D011108:Polymers; D013876:Thiophenes; D014025:Titanium; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D009570:Nitriles; D009687:Nuclear Proteins; D011108:Polymers; D013876:Thiophenes; C100379:nuclear matrix protein 22; C009495:titanium dioxide; C066730:polythiophene; C011206:cyanogen; D006108:Graphite; D003300:Copper; D014025:Titanium
keywords: Cu(2+) doped titanium dioxide; Multi-amplification; Photoelectrochemical immunoassay; Polythiophene; Sensitized g-C(3)N(4) nanosheet