Portable mercury sensor for tap water using surface plasmon resonance of immobilized gold nanorods

► The surface plasmon resonance of immobilized gold nanorods was used to quantify mercury in tap water. ► Glass slides were functionalized with MPTMS and chemically bound to nanorods. ► The immobilization on the surface improves the sensitivity of nanorods for mercury. ► The immobilization on the surface improves the limits of mercury detection.