Voltammetric Bioassay of Caffeine using Sensor Implant

Abstract

In this article, we examined the performance of the voltammetric assay of caffeine using DNA immobilized onto a carbon nanotube paste electrode (DPE) and compared it with that of an ordinary carbon nanotube paste electrode (PE). Under optimal conditions, the working ranges for caffeine were from 0.1 to 12 mg l(-1) (for DPE) and 30-230 mg l(-1) (for PE). Detection limits (DLs) of 0.068 mg l(-1) (3.50 x 10(-7) M) DPE and 9.94 mg l(-1) (5.12 x 10(-5) M) PE were obtained and the relative standard deviation at the caffeine concentration of 5.0 mg l(-1) was 0.064% (n = 15) DPE under optimum conditions. The sensor could be implanted in a leaf skin or animal brain cell, which can then be interfaced with an electrochemical workstation. It can be used in real-time in vivo caffeine analysis in a live cell or leaf skin.

Toxicological Investigation of Radioactive Uranium in Seawater

“…The detection limits of such methods are high, however, and the mercury sensor is environmentally toxic. In this study, more sensitive DNA immobilized (Ly et al ., 2009) on a graphite working (Ly et al ., 2011) probe was sought for uranium detection. DNA on a carbon-immobilized bond has hybridization efficiency (Ly et al ., 2008) , and its catalytic structure is capable of specific interaction (Ly et al ., 2009) .…”

“…In this study, more sensitive DNA immobilized (Ly et al ., 2009) on a graphite working (Ly et al ., 2011) probe was sought for uranium detection. DNA on a carbon-immobilized bond has hybridization efficiency (Ly et al ., 2008) , and its catalytic structure is capable of specific interaction (Ly et al ., 2009) . For this reason, the developed method is sufficiently simple and more compact, with a fast stripping time of only 30 s. These advantages can enable the developed method to attain a lower detection limit compared to the existing methods applied to seawater assay for energy sites.…”

Simultaneous Electrochemical Determination of Caffeine and Vanillin by Using Poly(Alizarin Red S) Modified Glassy Carbon Electrode

“…Electroanalytical methods have been commonly exploited as cheap, speedy, and simple options to modern separation and spectral methods. Over the years, to improve the sensitivity and long-term stability of the electrodes, the bare electrodes altered with several electrode modifiers such as nafion, conducting polymers, molecularly imprinted polymers, metal nanoparticles, carbon nanotubes (CNTs), and graphene were used for the individual determination of CAF (Švorc 2013;Brunetti et al 2007;Sun et al 2011a;Yang et al 2010;Sun et al 2011b;Amare and Admassie 2012;Wang et al 2004;Wei et al 2009;Xiong et al 2013;Lu et al 2012;Alizadeh et al 2010;Aklilu et al 2008;Ly et al 2008;Ly et al 2009;Habibi et al 2012;Martínez-Huitle et al 2010;Guo et al 2011;Yardım et al 2013) and VAN (Zheng et al 2010;Bettazzi et al 2006;Luque et al 2000;Peng et al 2012;Kong et al 2010;Deng et al 2015;Shang et al 2014;Luo and Liu 2012;Xinying 2014;Chethanaa et al 2012). It was noted that determination of CAF has predominantly been performed by voltammetric methods (Švorc 2013).…”