Black phosphorous quantum dots for signal-on cathodic photoelectrochemical aptasensor monoitoring amyloid β peptide

In this paper, a quantitative cathodic photoelectrochemical aptasensor is described by using black phosphorous quantum dots (BPQDs) as photoactive material and assisted by heme as electron acceptor for sensing of amyloid beta peptide (A beta). Specifically, BPQDs were synthesized by solvothermal method and characterized by various techniques. The as-prepared BPQDs were assembled on the transparent indium tin oxide electrode, and the positively charged poly-L-lysine (PLL) was then absorbed onto BPQDs via electronic interaction. Subsequently, the aptamer as the specific recognition element for A beta oligomer was introduced on the BPQDs-PLL modified electrode. After bound with heme to form A beta-heme complex, A beta oligomer was simultaneously captured by the aptamer on the electrode, resulting in an enhanced photocurrent response. Under the optimized conditions, the present PEC sensor reveals a good linear response to Ab peptide ranging from 1.0 fM to 100 nM with a detection limit of 0.87 fM. The present signal-on cathodic PEC bioassay possesses the potential to create a new paradigm in amplified PEC assays that could provide outstanding performance for bioanalysis. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, a quantitative cathodic photoelectrochemical aptasensor was developed using black phosphorous quantum dots as the photoactive material and heme as the electron acceptor for sensing amyloid beta peptide. The sensor exhibited a good linear response range and a low detection limit, showing promising performance in bioanalysis applications.