Browsing by Author "Di Lauro, Michele"
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- Neuromorphic organic devices that specifically discriminate dopamine from Its metabolites by nonspecific interactionsPublication . Giordani, Martina; Sensi, Matteo; Berto, Marcello; Di Lauro, Michele; Bortolotti, Carlo Augusto; Gomes, Henrique Leonel; Zoli, Michele; Zerbetto, Francesco; Fadiga, Luciano; Biscarini, FabioSpecific detection of dopamine (DA) is achieved with organic neuromorphic devices with no specific recognition function in an electrolyte solution. The response to voltage pulses consists of amplitude-depressed current spiking mimicking the short-term plasticity (STP) of synapses. An equivalent circuit hints that the STP timescale of the device arises from the capacitance and resistance of the poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) in series with the electrolyte resistance. Both the capacitance and resistance of PEDOT:PSS change with solution compositions. Dose curves are constructed from the STP timescale for each DA metabolite from pM to mM range of concentrations. The STP response of DA is distinctive from the other metabolites even when differences are by one functional group. Both STP and sensitivity to DA are larger across the patho-physiological range with respect to those to DA metabolites. Density functional theory calculations hint to a stronger hydrogen bond pattern of DA ammonium compared to cationic metabolites. The exponential correlation between STP and the binding energy of DA metabolites interacting with PEDOT:PSS indicates that the slow dynamics of ionic species in and out PEDOT:PSS is the origin of the neuromorphic STP. The sensing framework discriminates differences of nonspecific interactions of few kcal mol(-1), corresponding to one functional group in the molecule.
- Whole organic electronic synapses for dopamine detectionPublication . Giordani, Martina; Di Lauro, Michele; Berto, Marcello; Bortolotti, Carlo A.; Vuillaume, Dominique; Gomes, Henrique L.; Zoli, Michele; Biscarini, FabioA whole organic artificial synapse has been fabricated by patterning PEDOT:PSS electrodes on PDMS that are biased in frequency to yield a STP response. The timescale of the STP response is shown to be sensitive to the concentration of dopamine, DA, a neurotransmitter relevant for monitoring the development of Parkinson's disease and potential locoregional therapies. The sensitivity of the sensor towards DA has been validated comparing signal variation in the presence of DA and its principal interfering agent, ascorbic acid, AA. The whole organic synapse is biocompatible, soft and flexible, and is attractive for implantable devices aimed to real-time monitoring of DA concentration in bodily fluids. This may open applications in chronic neurodegenerative diseases such as Parkinson's disease.