title: Visible-light driven photoelectrochemical immunosensor for insulin detection based on MWCNTs@SnS2@CdS nanocomposites.
abstract: In this work, a label-free photoelectrochemical (PEC) immunosensor was developed for ultrasensitive detection of insulin based on MWCNTs@SnS2@CdS nanocomposites. As graphene-like 2D nanomaterial, SnS2 nanosheets loaded on the conducting framework of multi-walled carbon nanotubes (MWCNTs) were adopted for the construction of immunosensor for the first time, providing a favorable substrate for in-situ growth of CdS nanocrystal that had suitable band structure matching well with SnS2. The well-matched band structure of these two metal sulfides effectively inhibited the recombination of photogenerated electron-hole pairs, thus improving the photo-to-current conversion efficiency. Besides, the introduction of MWCNTs facilitated electron transfer across the surface of electrodes, leading to a further increment of photocurrent. The as constructed label-free PEC immunosensor based on MWCNTs@SnS2@CdS nanocomposites exhibited excellent PEC performance for the detection of insulin. The concentrations of insulin could be directly detected based on the decrement of photocurrent that was brought by the increased steric hindrances due to the formation of antigen-antibody immunocomplexes. Under the optimal conditions, the PEC immunosensor had a sensitive response to insulin in a linear range of 0.1pgmL(-1) to 5ngmL(-1) with a detection limit of 0.03pgmL(-1). Meanwhile, good stability and selectivity were achieved as well. The design and fabrication of this PEC immunosensor based on MWCNTs@SnS2@CdS nanocomposites not only provided an ideal platform for the detection of insulin, but also opened up a new avenue for the development of immunosensor for some other biomarkers analysis.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Fan
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Xuehui
authors.initials: X
authors.lastname: Pang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D019187:Cadmium Compounds / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D007328:Insulin / Q000032:analysis*; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010783:Photometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013440:Sulfides / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D007328:Insulin; D037742:Nanotubes, Carbon; D013440:Sulfides; D017971:Tin Compounds; C034939:cadmium sulfide; C078041:tin sulfide
keywords: In-situ growth; Insulin; Label-free; MWCNTs@SnS(2)@CdS; PEC immunosensor