A Study on surface modification of electrochemical biosensors for disease diagnosis through biomarker detection

Abstract

The paradigm of next-generation medical technology was shifted towards patient-centered applications for pre-diagnosis, pre-management, and maintaining a healthy life. In response to this shift, this study focuses on modifying the surface of electrochemical sensors to sensitively and rapidly detect disease-related biomarkers. First, an electrochemical sensor was proposed to detect the leukemia biomarker prohibitin2 (PHB2) protein. This study utilized gold nanoparticles to enhance the electroactive surface area, selfassembled monolayers (SAMs) to increase the signal-to-noise ratio (SNR), and Square Wave Voltammetry (SWV) for precise signal processing. These techniques provide a sensitive sensor response to PHB2. The developed sensor achieved an experimental detection limit of 40 pg/mL in standard solutions with reproducibility within <5.2 %. Additionally, for cell lysates extracted from actual blood samples, the sensor demonstrated a detection limit (LoD) of 0.63 ng/mL, reproducibility within <6.4 %, and recovery rates ranging from 89.1 % to 104.7 %. Furthermore, the correlation coefficient (R²) between the proposed sensor and the standard analysis method (Sandwich-ELISA) for PHB2 extracted from blood samples of healthy and patient groups was confirmed to be 0.99. These results suggest that the developed PHB2 sensor can be a precise analytical tool for diagnosis and prognosis monitoring. Second, an electrochemical sensor was developed to evaluate white spot disease (WSD), which causes mass mortality in shrimp. This study used the outer membrane protein VP28 of the white spot virus as a biomarker for WSD. The sensor surface was imprinted with the VP28 as a template molecule by immobilization and then modified with the molecularly imprinted polymer (MIP) by electropolymerization.The MIP synthesis was controlled by cyclic voltammetry (CV) parameters and optimized via recorded differential pulse voltammetry (DPV). The recognition efficiency of the VP28 sensor was evaluated with the current changes depending on the VP28 binding within the MIP. The VP28 sensor exhibited proportional current signals in the 3–50 ng/mL concentration range, with a 7.8 ng/mL detection limit. It also showed approximately twice the signal difference for VP28 compared to other interfering antigens. These results demonstrated significant linearity and selectivity. It promises differentiated performance in future clinical samples. Further studies will involve morphological and chemical analysis of the VP28 sensor and performance validation using shrimp tissue samples. It was expected to be used in diagnosing white spot disease.