Nanoenabling electrochemical sensors for life sciences applications

Abstract

Abstract

Electrochemical Discrimination of Salbutamol from Its Excipients in VentolinTM at Nanoporous Gold Microdisc Arrays

“…The sponge-like 3D structure with interconnecting pores of 20-30 nm and ligaments of 30-50 nm that typifies NPG is shown in Figure 3d. In the presence of 1 mM FCA, the measured CVs at 10 mV s −1 displayed sigmoidal responses reaching a steady-state current, typical of a single electron oxidation occurring at a micron-scale electrode and consistent with comparable array types previously reported [67]. This confirmed that the performance of the on-chip three-electrode cell was not compromised by the reduced cell volume (~200 µL when using the on-chip pseudoreference electrode), the on-chip counter electrode dimensions or by electrical contact using spring-loaded probes.…”

“…As described in the experimental section, NPG modification experiments were performed at gold microdisc array working electrodes by electrodeposition at −1.19 V vs. SCE for 3 s in a solution of 100 mM KAg(CN) 2 and 20 mM KAu(CN) 2 in 250 mM Na 2 CO 3 at pH 13 to yield Au 0.18 Ag 0.82 , followed by etching of the silver component in 25% nitric acid for 2 min and was based on a process described earlier for modification of arrays of gold microbands and gold microdiscs [66,67]. CVs in 1 M NaOH over the range −0.90 to 0.90 V at 10 mVs −1 were recorded vs. SCE in between each step, as shown in Figure 3a.…”

“…Based on its aforementioned attractive characteristics, NPG is an ideal candidate as an electrochemical sensor [62,63]. It has been successfully exploited in sensing several important gas-phase (e.g., oxygen, carbon monoxide, carbon dioxide, hydrogen peroxide, nitric oxide, hydrazine) and liquid-phase analytes (e.g., glucose and other saccharides, ascorbic acid, dopamine, nitrite, sulphite, heavy metals, BPA, ammonia borane and borohydride), which are of particular relevance in medical [64][65][66][67], environmental [68,69], food safety [70,71] and energy applications, including fuel cells [54,[72][73][74][75][76][77][78].…”

Challenges in Electrochemical Aptasensors and Current Sensing Architectures Using Flat Gold Surfaces

“…Micro-and nano electrodes become very useful when a high parallelism of analysis is needed and when a low sample volume is required. While aspects regarded to nanoelectrodes physical properties, fabrication and advancements in analytical instrumentation have been reviewed elsewhere [28][29][30], many efforts are oriented to enhance electrode signal using novel redox molecules or improving experimental procedures.…”