Electrical noise in gold nanoparticle chemiresistors: Effects of measurement environment and organic linker properties

This study was conducted to assess and characterize the intrinsic electrical noise associated with thiolate functionalized gold nanoparticle films utilized as chemiresistor sensors. Recently, this sensor type has been demonstrated to have liquid-based sensing capabilities. Differences in the thermal noise component of the different thiolate functionalized nanoparticle films in ambient air and in deionized water are detailed. Comparable values are found between real impedance values and resistance values derived from the Nyquist equation, in the frequency domain, for differing chemical measurement environments. Voltage-biased studies in aqueous media demonstrate the device´s retention of the intrinsic 1/f noise, known to exist in gold nanoparticle chemiresistors operating in ambient air. These results have implications on the ultimate sensitivity of devices utilized for liquid-based analyte detection.