High-performance assaying cardiac troponin I using Bi-doped tin-based heterojunction in photoelectrochemical biosensing with the quencher of yolk-shell nanostructure

• Published in: Talanta (Oxford) 2024-09, Vol.277, p.126342, Article 126342
• Main Authors: Guo, Jiang, Kuang, Guangrong, Luo, Danling, Yu, Wanqing, Chen, Li, Fu, Yingzi
• Format: Article
• Language: English
• Subjects: biomarkers; biosensors; Cardiac troponin I; chemical bonding; detection limit; disulfides; Doping; electric current; energy; Heterojunction; hot water treatment; myocardial contraction; myocardial infarction; nanocomposites; nanogold; Photoelectrochemical biosensor; risk; synergism; tin dioxide; Yolk-shell
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2024.126342

Cardiac troponin I (cTnI), a protein regulating myocardial contraction, stands the premier biomarker for diagnosing acute myocardial infarction and stratifying heart disease risk. Photoelectrochemical (PEC) biosensing combines traditional PEC analysis with high bioconjugation specificity, rendering a prospective avenue for disease biomarker analysis. However, the performance of sensors often falls short due to inadequate photoelectric materials. Hence, designing heterojunctions with proper band alignment, effective transport and separation of photogenerated carriers is highly expected for PEC sensors. Meanwhile, doping as a synergistic strategy to tune the energy band edges and improve carrier transport in heterojunctions, can also enhance the sensing performance. In this work, bismuth-doped tin oxide and tin disulfide heterojunction (Bi–SnOS) was prepared via a simple one-step hydrothermal method and utilized as a highly sensitive platform. Integrating copper sulfide-coated nano-gold (Au@CuS), a yolk-shell shaped nanocomposites, as the double quenching probe, an excellent PEC biosensor was fabricated to assay cTnI via sandwich immunorecognition. Under optimal conditions, the proposed biosensor displayed a high-performance for cTnI in the range from 0.1 pg/mL to 5.0 ng/mL with a low detection limit (44.7 fg/mL, 3σ). The strong photocurrent response, high stability and suitable selectivity point out that the synergistic effect between heterojunction and doping provides a promising prospect for the design of new PEC materials. [Display omitted] •Bi–SnOS was first prepared by doping Bi into SnO2/SnS2 via hydrothermal method.•The band gap and energy band edge positions of SnOS were affected by the dopant.•Using Bi–SnOS to construct a high sensitivity cardiac troponin I PEC biosensor.•The yolk-shell nanostructure of Au@CuS distinctly reduce the photocurrent.