A Molecularly Imprinted Polymer Nanobodies (nanoMIPs)-Based Electrochemical Sensor for the Detection of Staphylococcus epidermidis

Highlights: This study presents a novel electrochemical sensor utilizing molecularly imprinted polymer nanobodies (nanoMIPs) for ultrasensitive and selective detection of Staphylococcus epidermidis. The sensor integrates nanoMIPs synthesized via solid-phase imprinting of whole bacteria onto gold screen-printed electrodes (AuSPE) functionalized with a self-assembled monolayer (SAM) of 16-mercaptohexadecanoic acid (MHDA). Electrochemical impedance spectroscopy (EIS) demonstrated a remarkable detection limit of 1 CFU/mL and a linear range of 10¹–10⁶ CFU/mL, outperforming conventional PCR, real-time PCR, and other biosensors. Selective binding was confirmed against E. coli and B. subtilis, validated by SEM/AFM characterization showing increased surface roughness and particle immobilization. The platform offers cost-effectiveness, rapid analysis (<30 min), and disposability, making it promising for real-time monitoring of biofilm-associated infections on medical devices, with potential applications in clinical diagnostics and infection control. What are the main findings? A nanoMIP-based electrochemical sensor was developed for detecting Staphylococcus epidermidis, achieving high specificity and sensitivity with a detection limit as low as 1 CFU/mL. This sensor demonstrates potential for application in medical diagnostics and contamination monitoring due to its simplicity, cost-effectiveness, and reliable performance. What is the implication of the main finding? The main finding of this study demonstrates that the developed nanoMIP-based electrochemical sensor effectively detects Staphylococcus epidermidis with high selectivity and an impressively low detection limit of 1 CFU/mL. This result highlights the sensor’s potential for application in medical diagnostics and safety monitoring of medical devices, addressing a critical need for rapid and precise bacterial detection. Methicillin-resistant Staphylococcus epidermidis (MRSE) contamination is commonly found on human skin and medical devices. Herein, we present a sensor utilizing molecularly imprinted polymer nanobodies (nanoMIP) for recognition and electrochemical impedance spectroscopy (EIS) to detect S. epidermidis. Sensor manufacturing involves synthesizing nanoMIP via solid-phase synthesis using whole bacteria as templates. Screen-printed gold electrode (AuSPE)-modified 16-mercaptohexadecanoic acid (MHDA) served to immobilize the nanoMIPs on the sensor surface through an amide bond, with the remaining functional groups blocked by ethanolamine (ETA). Scanning electron microscope (SEM) analysis of the modified AuSPE surface reveals immobilized spherical nanoMIP particles of 114–120 nm diameter, while atomic force microscope (AFM) analysis showed increased roughness and height compared to bare AuSPE. The sensor is selective for S. epidermidis, with a remarkable detection limit of 1 CFU/mL. This research demonstrates that the developed nanoMIP-based sensor effectively detects S. epidermidis. Further research will focus on developing protocols to integrate the nanoMIP-based EIS sensor into medical and industrial applications, ultimately contributing to improved safety for both humans and animals in the future.