A novel label free long non-coding RNA electrochemical biosensor based on green l-cysteine electrodeposition and Au–Rh hollow nanospheres as tags

Abstract

Nuclear paraspeckle assembly transcript 1 (NEAT1) that reflects whether the body's anti-HIV virus immunity is strong or weak is one of many long non-coding RNAs (lncRNAs). The effective detection of NEAT1 has great scientific significance and clinical value. However, the detection of lncRNA is difficult with existing methods. The quantification of lncRNA by electrochemical methods based on changes in circuit properties such as capacitance, conductance and resistance may solve this problem. In this study, we describe a new label-free strategy based on catalytic signal amplification with single-wall carbon nanotubes wrapped with Au–Rh hollow nanospheres (Au/Rh-HNP@SWCNT). This strategy is useful for detecting the lncRNA NEAT1. Firstly, L-cysteine (L-Cys) was electrodeposited onto a Au electrode and incubated in colloidal Au to fully expose all of the binding sites of the Au particles, which can bind to L-Cys through its thiol-group. It can take advantage of each surface of the Au nanoparticles that is bound to the capture probe, which contains a (GGG)₃ trimer that can bind to the electron mediator hemin. The results indicate that catalysis was noticeably enhanced and that the biosensor provided ultrasensitive detection of the lncRNA NEAT1. The linear calibration of the biosensor ranged from 1 fM mL⁻¹ to 100 nM mL⁻¹, and the limit of detection was 0.8863 fM mL⁻¹. This lncRNA biosensor based on Au/Rh-HNP@SWCNT complex signal amplification and an L-Cys Au nano-film exhibited acceptable reproducibility and clear selectivity. This strategy may provide a new alternative for clinical HIV diagnosis through the detection of NEAT1.