Baseline resistance cancellation circuit for high resolution thiolate-monolayer-protected gold nanoparticle vapor sensor arrays

Chemiresistive (CR) sensors and sensor arrays coated with thiolate-monolayer-protected gold nanoparticle (MPN) interfaces show great promise for high-sensitivity multi-vapor analysis but suffer from process variation and drift in baseline values. This paper describes a new readout circuit that cancels baseline resistance and compensates for baseline drift to achieve ppm resolution. Requiring only 5100μm
²
in a 0.5μm CMOS process, the circuit is well suited for high density on-chip CR sensor arrays. The resulting CR array microsystem introduces a valuable tool for monitoring environmental hazards including explosive compounds.