Chemical sensing based on double layer PHEMA polymer and platinum nanoparticle films

A sensing approach for automated and real-time pesticide detection in the scope of smart-farming

“…The mechanism for the detection of gaseous analytes by hybrid NP/polymer based sensors has been discussed extensively in previous publications ( Skotadis et al, 2012 , Skotadis et al, 2010 , Skotadis et al, 2013 , Tang et al, 2012 , Madianos et al, 2018 ). In brief, the polymer layer acts as the gas-sensitive and transducing layer of the device by absorbing gases that are present in its vicinity; different polymers present different selectivity/susceptibility towards different gases.…”

“…It is also worth noting that our proposed gas-sensors have been optimized ( Skotadis et al, 2012 ) in terms of the available fabrication parameters, where the nanoparticle surface coverage and the IDE gap have been found to have the most prominent effect on sensor performance. In fact, optimum sensing performance has been observed for devices with conductivity that lies in the intermediate transition state, just below the percolation threshold.…”

“…Optical lithography, the e-gun technique and lift-off have been employed in order to produce the IDEs. The NP layer has been fabricated and deposited on top of the IDEs in a single step, using a modified magnetron sputtering technique which allows for easy and precise control of the NP surface coverage as well as NP size; the experimental process for the fabrication of similar sensors to the ones reported herein has been discussed in length in previous publications by this group ( Skotadis et al, 2012 , Skotadis et al, 2013 ). The surface coverage of the devices discussed in this paper, has been selected according to previous results ( Bekyarova et al, 2004 ) and for maximum sensitivity; for this reason devices with a mean resistance in the range of 700 kΩ have been used ( Fig.…”

“…This component can be easily integrated in the gaiasense system since it is compact, has low power requirements and its output is the electrical resistance of the sensing array. Hybrid chemiresistors based on Pt NPs and polymeric coatings have been developed in the past by this group and have been used for the detection of humidity and other organic analytes ( Skotadis et al, 2012 , Skotadis et al, 2010 , Skotadis et al, 2013 , Tang et al, 2012 ), as well as of a standard-solution containing CPS and p-xylene (appropriate solute for CPS) ( Madianos et al, 2018 ). However, such experiments have focused on the sensors’ ability to discern between the actual pesticide active-substance (namely CPS) and the solutes (p-xylene and water).…”

Identification of Two Commercial Pesticides by a Nanoparticle Gas-Sensing Array

“…In the current paper, a gas-sensing array comprised of platinum (Pt) NP films covered by polymeric films is proposed as an "e-nose" system for the room-temperature detection of two commercially available pesticides, Nimrod and Chloract 48 EC. The sensors utilize previous experience of this group in the development and optimization of NP based gassensing devices for the detection of humidity, VOCs [24][25][26][27], and pesticides [28]. Up to now, the array-optimization process has mainly focused on enhancing device performance by improving its design as well as its fabrication process.…”