Silver nanoparticle’s size and morphology relationship with their electrocatalysis and detection properties

Abstract

The development of electrochemical sensors based on silver nanoparticles (AgNPs) is a prominent field for detecting different analytes; nonetheless, several parameters should be considered, particularly regarding the nanostructure. This work investigates the influence of the nanoparticle’s morphology over the methylene blue (MB) degradation reaction evaluated by electrochemical techniques. To this end, AgNPs were synthesized by photochemical means, and posteriorly, their morphology was modified through a light irradiation process at specific wavelengths to avoid the addition of any further reagent. The voltammetric results showed that AgNPs with a lower available surface area have a higher current response (catalytic activity) towards MB degradation. Further, it was demonstrated that the proper selection of morphology allowed a lower detection limit of MB than those reported in the literature and could distinguish between molecular processes occurring at the interface level properly. While additional work is required to finetune a sensor based on AgNP, our contribution sheds new light on the electrochemical relevance of morphology and surface area of AgNPs.