Controllable preparation of (200) facets preferential oriented silver nanowires for non-invasive detection of glucose in human sweat

Abstract

(200) facets preferential oriented Ag nanowires were controllably prepared by a simple modified one-step polyol method, in which Cl ions and polyvinyl pyrrolidone (PVP) were employed as nucleating agent and crystal plane inducer, respectively. The evolution in morphology and structure of Ag nanowires were systematically studied by field emission scanning electron microcopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), from which the optimum synthesis conditions for (200) preferentially oriented Ag nanowires were obtained. Based on further electrochemical studies including cyclic voltammetry (CVs) and amperometry analyses, it is interesting found that the enrichment of (200) facets in the Ag nanowires display higher electrocatalytic activity than those of (111) facets towards glucose oxidation. This is attributed that dominant activity (200) facets of Ag nanowires have relatively higher surface energy and stronger adsorption capacity for glucose molecules, which can provide better electrocatalytic performance. The non-enzymatic glucose sensor based (200) facets preferential oriented Ag nanowires exhibits wide linear range of 0.5–3442 ​μM, low detection limit of 0.5 ​μM, and sensitivity is estimated to be 3246.74 ​μA ​cm−2 ​mM−1. Furthermore, the Ag nanowires based non-enzymatic sensor was successfully used for non-invasive detection of glucose in sweat with high accuracy.

Keywords

• Ag nanowires
• (200) orientation
• Glucose detection
• High sensitivity
• Non-invasive
• Sweat