Efficient fluorescence and electrochemiluminescence dual-signal au nanoclusters-based portable antibiotic testing platform with super-wide detection range

The convenient detection of tetracycline (TC) residues has attracted considerable attention because irrational use of TC causes food pollution damaging the human health. Herein, a point-of-care testing (POCT) platform is established for the sensitive and specific determination of TC in a polydopamine-functionalised Eppendorf tube. In particular, TC can be efficiently recognised by an aptamer–antibody chimera to trigger visual fluorescence (FL) and electrochemiluminescence (ECL) ‘dual-signal’ response of gold nanoclusters. Consequently, the biosensor exhibits a wide detection range spanning from 5 fM to 1 μM, with low detection limits of 73 fM (visual FL) and 2.3 fM (ECL). Hence, it can be said that the POCT platform is superior to the enzyme-linked immunosorbent assay. The strategy utilises the strength of FL, i.e. visualisation, and that of ECL, i.e. high sensitivity, providing a guiding approach for the development of POCT in food security and environmental monitoring.