Electrochemical determination of paraquat in citric fruit based on electrodeposition of silver particles onto carbon paste electrode

Abstract

Carbon paste electrodes (CPEs) modified with silver particles present an interesting tool in the determination of paraquat (PQ) using square wave voltammetry. Metallic silver particle deposits have been obtained via electrochemical deposition in acidic media using cyclic voltammetry. Scanning electron microscopy and X-ray diffraction measurements show that the silver particles are deposited onto carbon surfaces in aggregate form. The response of PQ with modified electrode (Ag-CPE) related to Ag/CP loading, preconcentration time, and measuring solution pH was investigated. The result shows that the increase in the two cathodic peak currents (Peak 1 and Peak 2), under optimized conditions, was linear with the increase in PQ concentration in the range 1.0 × 10 mol/L to 1.0 × 10 mol/L. The detection limit and quantification limit were 2.01 × 10 mol/L and 6.073 × 10 mol/L, respectively for Peak 1. The precision expressed as relative standard deviation for the concentration level 1.0 × 10 mol/L (n = 8) was found to be 1.45%. The methodology was satisfactorily applied for the determination of PQ in citric fruit cultures.

Voltammetric behaviors of an emerging pollutant benzotriazole on multiwall carbon nanotubes (MWNTs)—Nafion modified electrode in various pH mediums

“…The dependence of the reduction current of 1.0 mmol L −1 BTA on the preconcentration time was studied. The current was found to be linearly dependent on the preconcentration time till 90 s, at this time corresponding to either saturation or an equilibrium surface coverage [28]. It also indicated a steady-state accumulation level of BTA at MWNTs-Nafion/GCE over 90 s. As MWNTs-Nafion/GCE requires an exposure time of at least 90 s in 1.0 mmol L −1 BTA, therefore, a preconcentration time of 120 s was used for the subsequent investigations.…”

Design of Electrochemically Modified fMWCNT‐pencil Graphite Electrode Decorated with Cu and Ag Nanofilm and its Electrocatalytic Behavior Towards Imazethapyr

“…In present study, nanoparticles of Silver and copper were used for utilizing the bimetallic features in electrochemical sensing platform. Ag and Cu are noble metals, non toxic, economic and both possess good electrical conductivity, while CuNPs possessing a narrow band gap of 1.21–1.51 eV . These nanoparticles were used in various electrochemical sensing and catalytic applications .…”

“…Ag and Cu are noble metals, non toxic, economic and both possess good electrical conductivity, while CuNPs possessing a narrow band gap of 1.21–1.51 eV . These nanoparticles were used in various electrochemical sensing and catalytic applications . The addition of AgNP with CuNP as bimetallic nanoparticle layer on MWCNTs have been attract considerable interest in surface modification because they provide high electrical conductivity, absorptivity, chemical stability, biocompatibility, large surface area that can offer more active sites and also provide extra roughness to the conductive sensing interface , , , .…”

Electrodeposition of Gold Films from a Glycerol Solution on Carbon Paste Electrode and the Effect of Chemical and Electrochemical Parameters of Electrodeposition on the Electrode Performance in Potassium Ferrocyanide Solution

“…[9][10][11][12][13][14][15][16] By electrodeposition also is possible to modify the CPE, producing nanoparticles or thin films which cover the graphite flake surface. [17][18][19][20][21][22][23][24][25][26][27][28][29] The modified CPE by metallic electrodeposits (gold, [17][18][19][20][21] bismuth, 22,23 palladium, [24][25][26] antimony, 27,28 silver, 29 etc.) has been employed at analysis of various analytes, for example: mercury(II) in water; 17 dopamine 18 and morphine 19 in the presence of ascorbic acid and uric acid; morphine in urine; 20 methadone in biological fluids; 21 heavy metals; 22,27 nitrobenzene; 23 electrooxidation of oxalic acid; 24 hydrogen peroxide, dopamine and ascorbic acid; 25 electrocatalytic oxidation of formaldehyde; 26 indium, thallium and zinc 28…”

“…has been employed at analysis of various analytes, for example: mercury(II) in water; 17 dopamine 18 and morphine 19 in the presence of ascorbic acid and uric acid; morphine in urine; 20 methadone in biological fluids; 21 heavy metals; 22,27 nitrobenzene; 23 electrooxidation of oxalic acid; 24 hydrogen peroxide, dopamine and ascorbic acid; 25 electrocatalytic oxidation of formaldehyde; 26 indium, thallium and zinc 28 and paraquat. 29 Although the use of metallic electrodeposit as modifier on the electrodes surfaces has been very studied and some electrochemical parameters (deposition potential and time deposition) of electrodeposition are investigated on the electrode response, 22,24 the effect of other electrodeposition parameters are not completely described in these papers, that is, it is not investigated which electrodeposition parameters are main factors or if these factors affect the electrode response by interations. 30 In this context, a factorial planning can be used as tool to find the main factors and its interactions.…”