Simultaneous Detection of Dopamine and Uric Acid on Indium Tin Oxides Modified with Cost‐effective Gas‐phase Synthesized Single Walled Carbon Nanotubes

Abstract

Cost‐effective gas‐phase synthesized single walled carbon nanotubes (SWCNTs) were first employed for the surface modification of indium tin oxides (ITO) via electrostatic coating of poly‐l‐lysine (PLL). Compared with control substrates of bare ITO and SWCNT‐PLL‐slide glasses, SWCNT‐PLL‐ITO, with high catalytic properties associated with large surface areas, showed significant improvement of electro catalytic activity toward the oxidation of dopamine (DA) and uric acid (UA). The cyclic voltammetric (CV) peak separation of oxidation for both DA and UA was estimated to be ∼ 0.13 V, which renders them capable of simultaneously detecting DA and UA in a mixed solution. The differential pulse voltammetry (DPV) technique was further performed to obtain a linear detection range of DA from 1.0 μM to 100 μM, and a detection limit of 1.0 μM was confirmed in the mixed solution. Furthermore, the practical analytical ability of the method was finally confirmed by selective detection of both DA and UA in human urine samples without any preliminary treatment, implying the feasibility of applying bio‐sensors in a low‐cost manner.

Carbon‐Nanotube‐Based Materials for Electrochemical Sensing of the Neurotransmitter Dopamine

“…The reasonable practical analytical ability was confirmed by viability of these biosensors towards the recognition of both DA and UA in human urine samples without any pretreatment. [47] A modified edge-plane pyrolytic graphite electrode (EPPGE) with SWCNT-iron (III) oxide (SWCNT/Fe 2 O 3 ) NPs was prepared by Adekunle et al [48] EPPGE-SWCNT-Fe 2 O 3 yielded a 7-fold increase in the DA detection response compared to a bare EPPGE, and 2fold higher detection response compared to an EPPGE-SWCNT. The sensitivity and LOD for DA was 3.44 μA μM À 1 and 0.36 μM respectively.…”

“…A peak separation of 0.13 V was measured between the oxidation peak of DA and UA, which renders them capable of DA and UA sensing at the same time in a mixed solution. The reasonable practical analytical ability was confirmed by viability of these biosensors towards the recognition of both DA and UA in human urine samples without any pretreatment …”

Progress in the Development of Active-Matrix Quantum-Dot Light-Emitting Diodes Driven by Non-Si Thin-Film Transistors

“…Despite the remarkable development, however, further research on AM-QLEDs driven by non-Si-based TFTs is required to realize display devices with advanced features, e.g., transparency, flexibility, and stretchability, which has rarely been reported so far [ 23 , 24 , 25 , 26 ]. This may be because the TFT backplane needs to meet more stringent requirements, such as good electrical properties to drive high current, low response to light from QLED, and endurance to the solution-based QLED fabrication processes [ 27 , 28 , 29 , 30 , 31 ].…”