Surface Requirements for Optimal Biosensing with Disposable Gold Electrodes

Abstract

Electrochemical biosensors are promising technologies for detection and monitoring in low-resource settings due to their potential for easy use and low-cost instrumentation. Disposable gold screen-printed electrodes (SPEs) are popular substrates for these biosensors, but necessary dopants in the ink used for their production can interfere with biosensor function and contribute to the heterogeneity of these electrodes. We recently reported an alternative disposable gold electrode made from gold leaf generated using low-cost, equipment-free fabrication. We have directly compared the surface topology, biorecognition element deposition, and functional performance of three disposable gold electrodes: our gold leaf electrodes and two commercial SPEs. Our leaf electrodes significantly outperformed the SPEs for reproducible and effective biosensing in a DNase I assay and are nearly an order of magnitude less expensive than the SPEs. Therefore, these electrodes are promising for further development as point-of-care diagnostics, especially in low-resource settings.

Electricity, chemistry and biomarkers: an elegant and simple package

“…We have also observed that these goldleaf electrodes provided more reproducible data with lower limits of detection as compared to the commercial ones (Zamani et al, 2021c). Despite the fact that several iterations of gold-leaf electrodes have already Viral genetic material is amplified isothermally.…”

“…We have also observed that these gold‐leaf electrodes provided more reproducible data with lower limits of detection as compared to the commercial ones (Zamani et al , 2021c). Despite the fact that several iterations of gold‐leaf electrodes have already been reported in the literature, we found no reports of direct comparisons between gold‐leaf electrodes and commercial screen‐printed electrodes, especially for biosensing applications.…”

“…Based on these differences, we further compared the ability of these electrodes to detect DNAse I endonuclease activity. We observed significant differences in our ability to detect this enzyme on DNA‐modified electrodes based on the underlying electrode morphology, with our gold‐leaf electrodes outperforming both types of the SPEs (Zamani et al , 2021c).…”

“…However, clever detection schemes combined with new platform technologies could help to decrease the time for detection and increase specificity. My group, for instance, works on developing electrochemical sensors to detect infectious disease agents by harnessing the inherent activity of microbes to capture them on an electrode surface (Fig 2; Klass et al , 2021); improving electrodes for detection by decreasing their cost and difficulty of manufacture (Zamani et al , 2021c); and incorporating biological amplification to increase selectivity and sensitivity (Zamani et al , 2021b). Our ultimate goal is to improve global health equity by decreasing the financial barriers to testing (Sofen & Furst, 2020; Castle et al , 2021; Zamani et al , 2021b).…”

“…These electrodes can be fabricated in nearly any setting as it involves making a sticker out of the gold leaf that can be applied to a transparent backing as the working and counter electrodes (Zamani et al , 2021b,c,). The sticker is cut from gold leaf on adhesive backing using a small cutter plotter.…”