Controlling parameters and characteristics of electrochemical biosensors for enhanced detection of 8-hydroxy-2\u2032-deoxyguanosine

Aline M Faria,Alexander Flacker,Elisa B M I Peixoto,Cristina B Adamo,Elson Longo,Talita Mazon

doi:10.1038/s41598-019-43680-y

Aline M Faria, Alexander Flacker + Show 4 more

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https://doi.org/10.1038/s41598-019-43680-y

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Abstract

This work discusses the parameters and characteristics required on the development of a scalable and reliable electrochemical sensor board for detecting 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative stress biomarker for diabetic nephropathy, cancer and Parkinson’s disease. We used Printed Circuit Board (PCB) technology to make a precise, low-cost bare sensor board. ZnO nanorods (NRs) and ZnO NRs: reduced graphene oxide (RGO) composites were used as a pathway for antibody immobilization on the working electrode (WE). The parameters and characteristics of the WE were controlled for enhancing the quality of the electrochemical sensor board. Thickness of the gold and the presence of ZnO NRs or their composite on the WE have influence on charge transference process and reproducibility of the sensor board. The amount of the antibody, and its incubation period are crucial to avoid saturation of the sites during immobilization step and reduce the cost of the sensor. Our ZnO NRs-based electrochemical sensor board showed high sensitivity and selectivity to 8-OHdG with detection capacity in the range of 0.001–5.00 ng.mL−1. The successful application of our immunosensor to detect 8-OHdG in urine was evidenced.

Highlights

This work discusses the parameters and characteristics required on the development of a scalable and reliable electrochemical sensor board for detecting 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative stress biomarker for diabetic nephropathy, cancer and Parkinson’s disease
In order to evaluate the conductivity and stability of our bare-sensor board, we tested the use of copper or gold films as working and counter electrodes
We tested gold deposited by an electrolytic method as working electrode (WE) and counter electrode (CE)

Summary

Introduction

This work discusses the parameters and characteristics required on the development of a scalable and reliable electrochemical sensor board for detecting 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative stress biomarker for diabetic nephropathy, cancer and Parkinson’s disease. Our ZnO NRsbased electrochemical sensor board showed high sensitivity and selectivity to 8-OHdG with detection capacity in the range of 0.001–5.00 ng.mL−1. The development of precise diagnostic tools capable of evaluating the 8-OHdG concentration in real time is necessary[11] In this sense, electrochemical biosensors have allured much attention as a promising tool for detection of 8-OHdG. PCB shows the advantages of being relatively cheap and suitable for large scale-manufacturing, since the metallic deposition is made by electroplating Despite their advantages, few reports describe the importance of controlling the parameters of the manufacturing process, especially of the sensor board, in the improvement of biosensor properties. One of the ways to overcome these issues is controlling parameters and characteristics of the electrochemical sensing system, including board sensor

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