Fabrication and application of disposable 3D-printed gold electrodes for impedimetric biosensing of chemerin: a potential obesity biomarker

Obesity has more than tripled in prevalence since 1980, increasing the risk for chronic conditions like diabetes, cardiovascular diseases, and certain cancers. Adipose tissue, once seen as an energy reservoir, now plays an active role in hormone production, including adipokines like chemerin, which are linked to insulin resistance and metabolic disorders. This article explores chemerin's potential as a biomarker for early detection of insulin sensitivity, obesity, and diabetes, emphasizing the need for biosensor-based detection methods. Currently, chemerin analysis is only possible using the enzyme-linked immunosorbent assay (ELISA). In this study, a 3D-printed, gold-coated working electrode was developed to fabricate an impedimetric biosensor for detecting human chemerin. The working electrode was designed in SolidWorks and 3D printed, and then gold-coated using sputter coating. Self-assembled monolayers (SAMs) of 12-mercaptododecanoic acid (12-MDDA) were formed before immobilizing the chemerin-specific antibody. Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), and Single Frequency Impedance (SFI) analysis were employed throughout fabrication to examine chemerin-antibody interactions. Surface morphology was analyzed with Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The biosensor demonstrated a linear detection range of 2-20 ng mL^-1 with a sensitivity of 0.0227 ng mL^-1, limit of detection (LOD) of 0.0068 ng mL^-1, and limit of quantitation (LOQ) of 0.0227 ng mL^-1. The biosensor exhibited excellent repeatability and reproducibility, successfully detecting chemerin in human serum. The electrode material can be easily produced without specialized personnel and is much more cost-effective compared to commercially available gold electrodes.