Colorimetric based sensing of dopamine using ionic liquid functionalized drug mediated silver nanostructures

摘要

The present work reports the drug mediated synthesis of silver nanoparticles (AgNPs) for sensing of dopamine (biomarker Parkinson's disease and others). Augmentin drug was chosen because of functionalities and aromaticity in its structure which will not only work in the synthesis of AgNPs but also enhance the electron density on nanoparticles (NPs) for better sensing properties. 1-H-3-methylimidazolium acetate ionic liquid (IL) having characteristic properties of aromaticity and conductivity were coated on to the surface of NPs to further enhance the mentioned properties. The FTIR, Raman spectroscopy and XRD analysis demonstrate the characteristic peaks assigned to AgNPs. SEM analysis shows round shaped morphology and EDX showed strong band for AgNPs. TGA analysis showed maximum degradation at 340 degrees C for the prepared AgNPs. The functionalized AgNPs/IL was used in sensing of dopamine. Different reaction conditions have been optimized to find the optimal performance of AgNPs/IL such as; (a) pH (b) amount of Ag/IL (c) time of incubation; (d) temperature. The response time of the proposed sensor for dopamine detection was only 4 min with a visible colorimetric change from light grey to brown color. The proposed sensor showed a wide linear range (1 x 10(-8)-3.6 x 10(-6) M), low limit of detection 1.18 x 10(-7) M, and limit of quantification 3.92 x 10(-7) M with an R-2 value of 0.9997. The IL capped Ag nano assembly exhibited no reactivity towards folic acid, urea, ascorbic acid, Ca+2, K+ and was successfully used to quantify dopamine in physiological sample.