Facile In-Situ Synthesis of Biopolymer Capped Nano Sized Silver Particles: Smartphone Aided Paper-Based Selective Detection of CYS and TC Drugs in Biological and Drug Samples.

Herein we are reporting, the in-situ synthesis of polydopamine capped silver nanoparticles (PDA-AgNPs) and its cysteamine (CYS) and tetracycline (TC) drugs sensor applications. The synthesized PDA-AgNPs was characterized by UV–Visible, Fourier Transformed–Infrared, X-Ray Diffraction, Zeta Potential, and High Resolution-Transmission Electron Microscope techniques. We have utilized PDA-AgNPs as probes for the detection of CYS and TC by spectrophotometry method. The addition of CYS has led to a decrease in the absorption of PDA-AgNPs. The yellow color solution becomes colorless and observed the aggregated particles in the TEM image. In contrast, the addition of TC, into the same solution, absorption of PDA-AgNPs was increased. The color of the solution became dark yellow and the particles are obtained de-aggregation. Based on the Surface Plasmon Resonance (SPR) band absorption changes, the detection limit of CYS and TC was calculated to be 180 nM and 17 nM, respectively. Interestingly, 600-fold of common interferences did not interfere with the detection of CYS and TC. PDA-AgNPs was successfully utilized to detect CYS and TC in serum, urine, and drug samples. Finally, we have prepared a paper-based colorimetric kit for on-site monitoring of CYS and TC. [ABSTRACT FROM AUTHOR]