Arduino uno-based colorimetric sensor traction control system 3200 with AgNPs/PVP for Hg<sup>2+</sup> detection in river water of Aceh Selatan Regency, Indonesia

This study developed a colorimetric sensor using an Arduino Uno-based Traction Control System 3200 (TCS3200) color sensor and silver nanoparticles stabilized by polyvinyl-pyrrolidone (AgNPs/PVP) for detecting Hg(II) ions in river water samples from Aceh Selatan Regency.AgNPs/PVP exhibited localized surface plasmon resonance (LSPR) at 400 nm, with particles sized between 5.4 and 15.5 nm.Upon exposure to Hg 2+ , a visible color change indicated detection capability, with recovery rates of 97.3-100% and detection limits at 1.8 and 6 g/L, respectively.Colorimetric results matched UV-Vis spectrophotometry, validating reliability.This efficient method provides a viable option for Hg 2+ monitoring in environmental samples.