A mercury-free, electrochemical sensor is described that includes a self-assembled monolayer on a mesoporous support (SAMMS) composite and a fluoropolymer component that is deposited on a measurement surface. The SAMMS component provides outstanding metal preconcentration. The fluoropolymer component acts as an antifouling binder. The sensor can detect various metals at a low detection level in the presence of fouling agents and without sample pretreatment. The sensor is also able to detect mixtures of metals simultaneously with excellent single and inter-electrode reproducibility. Service lifetimes are excellent.