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

Abstract

A novel conductometric hydrogen sulfide (H 2 S) 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 À1 , 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 H 2 S was achieved at room temperature. In addition, excellent selectivity was demonstrated toward CO and SO 2 with minimum interference from NH 3 . 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.

Gold Nanoparticles Monolayer Doping PEDOT : PSS Janus Film for Hydrogen Sulfide Sensor

“…The linear I-V plots over a voltage range from À 5 to + 5 V confirmed the ohmic behavior of the PEDOT : PSS/AuNPs Janus film on interdigitated electrode [34]. The I-V characteristics are primarily determined by the intrinsic properties of the nanomaterials film including the conductivity of PE-DOT : PSS [35], and thus the ΔV/ΔI values also increased after absorption of H 2 S. The removal of metal-semiconductor junction leads to the amplification of the response to H 2 S because the AuNPs had been reacted [19,20]. Therefore, the Ohmic contact can be used to determine the amount of H 2 S according to the ΔV/ΔI values.…”

“…The chemiresistive sensor working theory usually could be attributed to two main factors: (i) the presence of CPs leads to the release of protons by reacting with H 2 S, (ii) the presence of gold nanoparticles causes the release of protons by reacting with H 2 S [2]. For Janus film, the formation of metal-semiconductor junction could suddenly drop electric resistance and the removal of metal-semiconductor junction would amplify electric resistance [19,20]. Therefore, Janus film formed with CPs and NPs has the metal-semiconductor junction which is highly sensitive to adsorption phenomena resulting in amplify of the response to H 2 S.…”

Intelligent Packaging Systems: Sensors and Nanosensors to Monitor Food Quality and Safety

“…Several authors have worked in the development of nanosensors. These NM are used in the detection of molecules, gases, and microorganisms and detection by surface enhanced Raman spectroscopy (SERS) [49]; nanosensors in raw bacon packaging for detecting oxygen [55]; electronic tongue for inclusion in food packaging consisting of an array of nanosensors extremely sensitive to gases released by spoiled food, giving a clear and visible sign if the food is fresh or not [52]; use of fluorescent nanoparticles to detect pathogens and toxins in food and crops [56], for example, detection of pathogenic bacteria in food (Salmonella typhimurium, Shigella flexneri, and Escherichia coli O157: H7), based on functionalized quantum dots coupled with immunomagnetic separation in milk and apple juice [57]; nanosensors to detect temperature changes [58,59], where food companies like Kraft Foods are incorporating nanosensors that detect the profile of a food consumer (likes and dislikes), allergies, and nutritional deficiencies [60]; nanosensors for the detection of organophosphate pesticide residues in food [61]; nanosensors to detect humidity or temperature changes due to moisture [62]; sensor for detecting Escherichia coli in a food sample, by measuring and detecting scattering of light by cellular mitochondria [63]; biosensor for instantly detecting Salmonella in foods [64] and sensor to detect CO 2 as a direct indicator of the quality of the food [65]; biosensor for the detection of the pathogen food, Bacillus cereus [66]. Research and development in nanosensors have led to important scientific advances that enable a new generation of these NM.…”

Voltage and current conditions for nanoparticle chain formation using dielectrophoresis

“…Nanoparticle trapping in a gap between electrodes through dielectrophoresis is used for the formation of micro-and nanostructures of nanoparticles [1][2][3] or the property measurement of nanoparticles [4][5][6][7][8]. In particular, the formation of a nanoparticle chain structure has been of great interest because of its application to micro-and nanodevices [9][10][11][12]. When a certain voltage is applied across a gap between electrodes covered with a nanoparticle dispersion, an electric field is generated around the gap.…”