Selective and Rapid Room Temperature Detection of H2S Using Gold Nanoparticle Chain Arrays

A novel conductometric hydrogen sulfide (H2S) sensor was fabricated by AC dielectrophoretic assembly of amino acid mediated grown gold nanoparticles across microfabricated gold electrodes. Excellent sensing performance toward hydrogen sulfide, including a sensitivity of 29.84% ppm(-1), a lower detection limit in the sub-ppm level, the upper detection limit of 2 ppm, and a response time of <20 s for 10 ppm H2S was achieved at room temperature. In addition, excellent selectivity was demonstrated toward CO and SO2 with minimum interference from NH3. Enhanced sensor performance may be attributed to the use of amino acid capped gold nanoparticles compared to thiolated gold nanoparticles and optimized assembly conditions to control the density of gold nanoparticle chains and electron transport properties.