Title : Novel concepts in ultrasensitive detection of emerging water contaminats for in-field, real-time, drinking water quality monitoring with chemical nanocomposite biosensors
Abstract:
Recently we combined ultra-sensitive gravimetric transduction by a 434 MHz two-port SAW resonator and gold electrodes with Electrochemical Impedance Spectroscopy (EIS) on the same device, utilizing the strong enhancing effect of the interdigitated microelectrodes of the SAW device. The emerging contaminant PFOS –“forever chemical” because of the very strong C-F bonds, among the most dangerous compound (USA EPA norms) of the 20 PFAS contaminants that have to be monitored following the latest (2020) EU directive on water intended for human consumption. It was very selectively captured and measured almost in real-time by a Langmuir-Blodgett (LB) monolayer from a mixture of the Metal-Organic (MOF) MIL-101(Cr) and different lipids and phospholipids [1]. This concept, but this time only AA or DPPENBD LB monolayers was tested for nonselective Volatile Organic Compounds (VOC) measurements in the gas phase [2]. The huge sensitivity, not fully disclosed yet (patents pending) is due not only to the new concepts in signal transduction (see Figure right), but also to the novel effects discovered over the last 38 years of the very special DPPE-NBD fluorescently head labeled phospholipid, which closely mimics the biomembrane lipid “sea” in which protein or other molecules are floating (see Figure left) [3, 4]. All the transduction electronics are palm-handsized and can be powered by a GPS tracker with satellite communication for planting the sensor before and after the city's water purification systems.
