Designing and fabrication of a novel sensitive electrochemical aptasensor based on poly (L-glutamic acid)/MWCNTs modified glassy carbon electrode for determination of tetracycline
“…Initially, graphite rods were impregnated with paraffin according to the previously reported procedure to form PIGE. 32 Then, an ethanolic solution of graphene oxide synthesized by modified Hummer's method 33 was drop casted onto the surface of PIGE and allowed to dry for few hours at room temperature. The electrode was further subjected to a reduction potential Figure 1.…”
Section: 3a Electrochemical Reduction Of Gomentioning
Gallic acid (GA) is one of the main phenolic components occurring naturally in plants and has been a subject of increasing interest owing to its antioxidant, anti-mutagenic and anti-carcinogenic properties. The present work describes a rapid and cost-effective analytical procedure for the determination of gallic acid. Poly-Glu/rGO electrode was fabricated by the electro-polymerisation of glutamic acid on reduced graphene oxide (rGO) modified paraffin impregnated graphite electrode (PIGE). The modified electrode was characterized by SEM, AFM and ATR-IR. The electrochemical behavior of gallic acid at the modified sensor was studied by voltammetric and amperometric techniques under optimized conditions in pH 5 acetate buffer. The electrode showed good linear response towards the determination of gallic acid over the range of 0.03-480 µM with 0.01 µM as the detection limit for voltammetric technique and the amperometric technique showed a linear range of 1-17 µM with 0.33 µM as the detection limit. The electrode also showed good stability and reproducibility with a sensitivity of 0.97 µM/µA. The proposed method can be applied to detect GA in real samples with satisfactory results.
“…Initially, graphite rods were impregnated with paraffin according to the previously reported procedure to form PIGE. 32 Then, an ethanolic solution of graphene oxide synthesized by modified Hummer's method 33 was drop casted onto the surface of PIGE and allowed to dry for few hours at room temperature. The electrode was further subjected to a reduction potential Figure 1.…”
Section: 3a Electrochemical Reduction Of Gomentioning
Gallic acid (GA) is one of the main phenolic components occurring naturally in plants and has been a subject of increasing interest owing to its antioxidant, anti-mutagenic and anti-carcinogenic properties. The present work describes a rapid and cost-effective analytical procedure for the determination of gallic acid. Poly-Glu/rGO electrode was fabricated by the electro-polymerisation of glutamic acid on reduced graphene oxide (rGO) modified paraffin impregnated graphite electrode (PIGE). The modified electrode was characterized by SEM, AFM and ATR-IR. The electrochemical behavior of gallic acid at the modified sensor was studied by voltammetric and amperometric techniques under optimized conditions in pH 5 acetate buffer. The electrode showed good linear response towards the determination of gallic acid over the range of 0.03-480 µM with 0.01 µM as the detection limit for voltammetric technique and the amperometric technique showed a linear range of 1-17 µM with 0.33 µM as the detection limit. The electrode also showed good stability and reproducibility with a sensitivity of 0.97 µM/µA. The proposed method can be applied to detect GA in real samples with satisfactory results.
“…This can be attributed to the response of the ferricyanide solution on the surface of the electrode. The increase in the TET concentration hinders the ferricyanide solution to react with the electrode surface (Benvidi et al., 2018). Fig.…”
Section: Resultsmentioning
confidence: 99%
“…Previous studies (Asadollahi-Baboli and Mani-Varnosfaderani, 2014; Kalambate et al., 2015; Saha et al., 2012; Wang et al., 2011; Wang et al., 2012) reported that electrodes modified with AuNPs showed better limits of detection. Multi-walled carbon nanotubes (MWCNTs) are used in electrode modification due to their remarkable electrochemical properties and numerous electrochemically active sites (Benvidi et al., 2018; Gholivand, 2013; Vega et al., 2007; Wong et al., 2015; Zhan et al., 2016). When AuNP is combined with MWCNT, the performance of the final composite material is improved, since the AuNP/MWCNT composite has the individual properties of both constituent components as well as a synergistic effect (Da Silva et al., 2018).…”
Glassy carbon electrodes (GCE) were modified with gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNTs) by means of sputtering and electrodeposition. The electrodeposited MWCNT on gold coated GCE exhibited the optimum performance as characterized using cyclic voltammetry. The limit of detection and limit of quantitation were found to be 42 ppb and 139 ppb, respectively. The modified electrode was used as working electrode in differential pulse voltammetry to detect tetracycline (TET) residues in the eggs, wings, liver, breast, and thigh, of organic as well as non-organic chicken bought from a local supermarket. The highest concentration in the eggs, wings, liver, breast, and thigh were found to be 5.9 ppm, 2.0 ppm, 1.4 ppm, 1.3 ppm, and 1.2 ppm for organic chicken and 8.70 ppm, 4.8 ppm, 4.3 ppm, 3.3 ppm, and 2.7 ppm for the corresponding parts in non-organic chicken, respectively. The obtained concentrations were remarkably greater compared to the maximum residual limit released by the Codex Alimentarius Commission.
“…In this study, the sensor system was characterized with Scanning Electron Microscopy (SEM), CV and EIS. The aptasensor can be successfully used for the analysis of tetracycline in drug formulations and spiked honey samples [64].…”
Section: Aptasensors For Small Molecules Detectionmentioning
Aptamers are short length, single‐stranded DNA or RNA affinity molecules which interact with any desired targets such as biomarkers, cells, biological molecules, drugs or chemicals with high sensitivity. They have been extensively employed for medical applications due to having more advantages than the antibodies such as easier preparation and modification, higher stability, lower batch‐to‐batch variability and cost. Moreover, aptamers can be easily integrated efficiently with sensors, biosensors, actuators and other devices. In this review article, different applications of aptamers for biological and chemical molecules detection within the scope of electrochemical methods were presented with recent studies. In addition, the present status and future perspectives for highly‐effective aptasensors for specific and selective analyte detection were discussed. As in stated throughout the review, combining of extraordinary properties of aptamers with the electrochemical‐based biosensors could have improved the sensitivity of the assay and reduced limit of detection.
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