Eco-friendly copper nanomaterials-based dual-mode optical nanosensors for ultrasensitive trace determination of amoxicillin antibiotics residue in tap water samples

In this study, we have developed, for the first time, a colorimetric and surface-enhanced Raman scattering (SERS) dual-mode sensing platform for sensitive amoxicillin (AMX) detection by employing electrochemically-synthesized copper nanoparticles (CuNPs) and copper-graphene oxide (Cu-GO) nanocomposites with low cost and high purity. The obtained results revealed that Cu-GO-based colorimetric nanosensor exhibited high sensitivity with AMX antibiotics in a linear working range from 5 to 50 µM with a limit of detection (LOD) of 1.71 µM, which was 1.3 times lower than that of CuNPs-based colorimetric nanosensor (2.17 µM). More interestingly, Cu-GO-based SERS nanosensor has a linear range from 0.01 to 1000 µM and a LOD value ∼x223C 0.0012 µM, which was ∼x223C 13 times lower than CuNPs-based SERS sensor (0.0152 µM). Our developed dual-mode optical nanosensors also exhibited good practical applicability for AMX detection in real tap-water samples with high accuracy as recovery rates were calculated about 95% and RSDs were less than 5%.