Toward non-invasive diagnostics through AuNSs@Nano-MIP biosensor for sensitive lactoferrin detection in sweat

Abstract

Lactoferrin (LF) is implicated in a wide range of health conditions, including inflammatory disorders such as Inflammatory bowel disease (IBD), autoimmune pathologies, and various cancers. Here, we present a novel biomimetic biosensor for non-invasive sweat-based detection of LF. The biosensor incorporates gold nanostars (AuNSs, approximately 80 nm), synthesized via a cost-effective one-step fabrication method. AuNSs' sharp tips, approximately 10-20 nm, enhance the electroactive surface and electron transfer in the electrochemical biosensor. The sensor, composed of AuNSs and a molecularly imprinted polymer (MIP) layer, was validated by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and cyclic voltammetry (CV). In addition, a microfluidic patch was designed to collect sweat from three distinct body regions of four valountiers, yielding an average collection time of approximately 15mins and a sweat volume ranging 20-100 muL. This biomimetic biosensor demonstrated reliable performance in complex biological matrices, providing a measurable electrochemical response to LF across a concentration range of 2-2000 ng/mL, with sensitivities of 2.54 muA mL/ng and 2.30 muA mL/ng in LF-spiked PBS and sweat, respectively. The biosensor achieved a limit of detection (LOD) of 1.74 ng/mL in LF-spiked PBS and 1.92 ng/mL in LF-spiked sweat. Additionally, the biosensor showed reproducibility across four independently fabricated devices, with relative standard deviation (RSD) values of <5 at different concentrations. Overall, this study presents a step toward developing affordable, biomimetic wearable technologies for sweat-based detection of inflammatory biomarkers such as LF. By enabling non-invasive monitoring, this approach may offer valuable insights into disease recurrence and progression, with potential applications across a range of inflammatory and immune-related disorders.