Biosensors based on nucleic acid-structured electrochemiluminescence are rapidly developing for medical diagnostics. Here, we build an automated DNA molecular machine on Ti3C2/polyethyleneimine-Ru(dcbpy)3 2+@Au composite, which alters the situation that a DNA molecular machine requires laying down motion tracks. We use this DNA molecular machine to transduce the target concentration information to enhance the electrochemiluminescence signal based on DNA hybridization calculations. Complex bioanalytical processes are centralized in a single nucleic acid probe unit, thus eliminating the tedious steps of laying down motion tracks required by the traditional molecular machine. We found a detection limit of 0.68 pM and a range of 1 pM to 1 nM for the analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific DNA target. Recoveries range between 96.4 and 104.8% for the analysis of SARS-CoV-2 in human saliva.
Supplementary information: The online version contains supplementary material available at 10.1007/s10311-022-01434-9.
Keywords: Automated molecular machine; Modular reaction; SARS-CoV-2 monitoring; Saliva environmental testing; Ti3C2-based composites.
© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2022.