Synthesis of Hydrotalcite-Supported CdTe Semiconductor Nanocrystals for Electrochemical Detection of Ciprofloxacin

Abstract

In this work, CdTe quantum dots (QDs) were controllably grown onto the surface of layered double hydroxide (LDH) aiming to develop a sensitive and selective method for the electrochemical detection of ciprofloxacin (CPX). Emission and absorption spectroscopy results as well as high-resolution transmission electron microscopy (HRTEM) images evidenced the formation of LDH/QD hybrid material. Unmodified carbon paste electrodes (CPE) as well as CPE chemically modified (MCPE) with native LDH and with the LDH/QD hybrid were prepared for CPX detection, revealing that MCPE-LDH/QD had the highest sensitivity for the detection of ciprofloxacin. Optimum detection conditions included a modifier dosage of 20% in MCPE, Britton-Robinson (BR) buffer (pH 6.0) as analytical medium, 300 s accumulation time and a scanning rate of 20 mV s-1. Linear current versus concentration curve was observed from 2.5 × 10-8-1.2 × 10-5 mol L-1 (coefficient of determination (R 2) = 0.995), with sensitivity (limit of detection (LOD) = 4.2 × 10-8 mol L-1 ; limit of quantification (LOQ) = 1.3 × 10-7 mol L-1), precision (relative standard deviation (RSD) = 3.0%), accuracy (94.0%) and satisfactory selectivity in the presence of Zn 2+ , Fe 2+ , Cu 2+ , citric acid and ascorbic acid. Tests of CPX determination in commercial 500 mg ciprofloxacin tablets evidenced the applicability of the method.

Electrochemistry: Modified Electrodes and their Potentialities

“…Esse termo designa a inserção de espécies quimicamente ativas à superfície dos eletrodos, com a finalidade de intensificar as propriedades eletroanalíticas, melhorando as interações com o analito, aumentando a reatividade e a seletividade entre solução/eletrodo. [45][46][47][48][49][50][51][52] Esse dispositivo permitiu estudos mais complexos para diferentes analitos e amostras reais. O eletrodo de mercúrio gotejante foi o mais utilizado para fins eletroanalíticas, entretanto a estreita faixa de potencial na região anódica e a alta toxicidade, impulsionou a busca por novos materiais modificadores.…”

“…), 49,52 organometálicos 16,54 e nanomateriais. 51,56 Constatou-se que a grande parte dos analitos são compostos orgânicos e biológicos, com aplicações na área da saúde e meio ambiente. As aplicações objetivam uma melhora na qualidade de vida da sociedade, devido a detecção e monitoramento de diversas substâncias, tais como defensivos agrícolas, princípios ativos de medicamentos e estudo de perfis biológicos.…”

Turn-off/turn-on biosensing of tetracycline and ciprofloxacin antibiotics using fluorescent iron oxide quantum dots

“…Various techniques have been reported for the detection of TCy, such as high-performance liquid chromatography (HPLC), 8 enzyme-linked immunosorbent assay (ELISA), 9 electrochemical, 10 spectrophotometry, 11 and immunochromatographic assay. 12 General methods are also available for the detection of CPx, including HPLC, 13 ELISA, 14 electrochemical methods, 15 and spectrophotometry. 16 Although HPLC methods are sensitive, the complexity of the operation and other high costs restrict their utility.…”

Eco-Friendly Elaborated Clay-Supported Reduced Graphene Oxide for the Determination of Antibacterial Ciprofloxacin in Wastewater, Urine, and Drug Samples

“…[3][4][5][6][7][8] Recently, the electrochemical monitoring platforms for sensing harmful residues have shown great potential due to their tremendous performance, based on modified electrodes using advanced materials. [9][10][11][12][13][14] Therefore, several components have been reported for the advancement of electro-analytical sensors for electrochemical analysis of Cipro using different materials as modifiers, including layered double hydroxide quantum dots (LDH/QD), 15 samarium oxide nanorods (Sm 2 O 3 −9-3), 16 multiwalled magnetic carbon nanotubes, and molecularly imprinted polymer (MMWCNTs-MIP), 17 chitosan-coated ferrite oxide magnetic nanoparticles (CMNPs), 18 and copper-zinc-ferrite nanoparticles (CZF), 19 2-amino-5-mercapto-1,3,4-thiadiazole with silver (AMT-Ag). 20 In order to elaborate a sensitive, affordable, selective, and environmentally friendly device, we synthesized the rGO-Clay as modifier for CPE.…”