Synthesis, Characterisation and Cytotoxicity of Gold Nanowires for Ultra-Sensitive Biosensor Development

Abstract

With the long-term goal of developing an ultra-sensitive microcantilever-based nanobiosensor for versatile biomarker detection, new controlled bioreceptor-analytes systems are being explored to overcome the disadvantages of conventional ones. Gold nanowires (AuNWs) have been used as a probe to overcome the tolerance problem that occurs in response to changes in environmental conditions. However, the cytotoxicity of AuNWs is still unclear. Here, we examined the cytotoxicity of AuNWs systems using both commercial and as-synthesised AuNWs. In vitro experiments show that commercial AuNWs with an average quoted length of 6 µm are highly toxic against Gram-negative Escherichia coli (E. coli) at 50 µg/ml. However, this toxicity is due to the presence of CTAB surfactant no by the nanostructure. Conversely, the as-synthesised AuNWs with an average length of 9.5 µm show non-cytotoxicity even at the maximum viable concentration (330 µg/ml). These findings may lead to the development of potentially life-saving cytotoxicity -free nanobiosensors for an early diagnostic of potential diseases.