Electrochemical sensor for the detection of ppq-level Cd2+ based on a multifunctional composite material by fast scan voltammetry

Nie

ACS Sustainable Chem. Eng.

et al. 2022

Driven by the urgent requirement to monitor the trace amount of heavy metal ions, a novel electrochemical sensing platform is constructed by surface modification of magnetic NiFe 2 O 4 nanoparticles with polypyrrole (PPy). This NiFe 2 O 4 /PPy nanocomposite has a unique three-dimensional network architecture. Under the optimized experimental conditions, the fabricated sensor exhibits enhanced sensing performance for selective recognition of trace Pb 2+ in the range of 0.1−2.1 μM by square wave anodic stripping voltammetry. The sensitivity of a NiFe 2 O 4 /PPydecorated glassy carbon electrode (GCE) toward Pb 2+ is verified to be superior to that of both bare GCE and NiFe 2 O 4 -decorated GCE, and an extremely low detection limit of 3.9 nM (S/N = 3) can be achieved. The accurate detection of Pb 2+ is also challenged by various aqueous media and satisfactory recoveries varied from 98−107%, endowing it with great prospects in the analysis of real water samples. Moreover, the interferences from coexisting ions such as Cd 2+ , Fe 3+ , Zn 2+ , Ni 2+ , Cu 2+ , and Na + can be ignored to some extent. The present study not only provides a new candidate for the efficient detection of Pb 2+ but also sheds light on exploring advanced electrode materials to rationally design sensing interfaces.

Section: Resultsmentioning

confidence: 86%

“…At higher pH values, the stripping signals display a slight decrease, which might be caused by the formation of metal ion hydroxide complexes, thereby inhibiting the capture of Pb 2+ . 35,36 Based on the above results, a pH of 5.0 was accepted.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

PPy-Functionalized NiFe₂O₄ Nanocomposites toward Highly Selective Pb²⁺ Electrochemical Sensing

Nie

ACS Sustainable Chem. Eng.

et al. 2022

Adv Materials Technologies

“…The linear plot of ν versus I pa and I pc shows that the redox reaction of Cd 2+ followed the surface‐confined adsorption‐controlled process at the CoS‐NGQD/Pt@Pd/SPE, and the linear equation can be written as I pa = 3.8494ν (mV s −1 )+3.8892 (R 2 = 0.9911) and I pc = −4.1908ν (mV s −1 )−6.4833 (R 2 = 0.9915) (Figure 3e). [ 70 ] Because the peak‐to‐peak separation potential ( E p ) of the anodic and cathodic peaks is greater than 200/n (mV) for the diffusionless electrochemical system, the Laviron equation was used to calculate the charge transfer coefficient (α) and electron transfer rate constant ( k s ) by fitting the linear plot of log ν versus E pa and E pc (Figure 3f). [ 71 ] The linear relationship between log ν versus E pa and log ν versus E pc is displayed in Figure 3f, where the linear correlation equation was obtained as E pa (V) = 0.06649 log ν (mV s −1 )−0.8474 (R 2 = 0.9965) and E pc (V) = −0.05836 log ν (mV s −1 )−0.9979 ( R 2 = 0.9912).…”

Section: Resultsmentioning

confidence: 99%

SARS‐CoV‐2 N Gene‐Targeted Anodic Stripping Voltammetry Sensor Using a Novel CoS‐NGQD/Pt@Pd Platform and Au‐DNA‐CdTe QD Probe

Selvam

Phan

Cho

2023

Rapid screening of individuals infected with severe acute respiratory syndrome‐coronavirus‐2 (SARS‐CoV‐2) is necessary to contain contagion in a large population. Nucleic acid‐based gold standard assays are time‐consuming, and nucleic acid amplification is mandatory and expensive, impeding the containment of the coronavirus disease 2019 (COVID‐19) outbreak. To overcome the aforementioned disadvantages, this study deals with a specially designed gold (Au)‐deoxyribonucleic acid (DNA)‐cadmium telluride (CdTe) quantum dot (QD) probe to target two sections of the nucleocapsid (N) gene of SARS‐CoV‐2 ribonucleic acid (RNA) of three variants (B.1.1.529, B.1.617.2, and B.1.351). A duplex‐specific nuclease (DSN)‐assisted highly selective release of signaling probes enable higher specificity, and an Au‐supported DNA probe is incorporated to carry many CdTe QD signaling probes. After dissolution, the generated Cd2+ ions are quantified at the novel cobalt sulfide (CoS)‐nitrogen‐doped graphene QD (NGQD)/platinum (Pt)@palladium (Pd) electrode with extraordinary sensitivity through square wave anodic stripping voltammetry (SWASV). The developed sensor exhibits a wide range of detection (10 to 108 copies µL−1) and a lower detection limit (0.12 copies µL−1), without any amplification. The selectivity of the sensor is tested against MERS and HCoV‐NL63, and real‐time detection is performed on heat‐inactivated viral samples, which show excellent selectivity.

Port. Electrochim. Acta

“…DPAdSV is very sensitive, and it can be used to analyze very small concentrations (µg/L or ng/L) of species in solutions (14,20). For heavy metals, the following voltammetric methods have previously been reported: AdSV, for Cu and Cd (21,22); DPAdSV, for Cr (23); FSV, for Cd (24); and AdSV-RSM, for Cu (25). However, the methods are still carried out individually, which consumes a lot of time and chemical reagents, when the metals are analyzed in nature.…”

Section: Introduction mentioning

confidence: 99%

Simultaneous DPAdSV for Heavy Metals Determination in the Seawater of a Former Bauxite Mining Area

Pardi¹,

Fitriyah²,

Silitonga³

et al. 2023

The widespread use of HMDE for multi-ionic analysis is mainly explained by the following factors: excellent reproducibility, due to the electrode surface ease of renewal, for preventing hysteresis; wide Ec; ability to forming amalgams with many redox-active metal ions; and (sub)nanomolar detection limits, which have unique capabilities for multi-metal determination. In this research, selectivity and sensitivity for Pb, Cd and Zn simultaneous determination, by DPAdSV, using HMDE as WE and CCA as a ligand, were tested. This method is based on the deposition of CCA-metals on Hg electrodes. The instrumental and chemical parameters that could improve measurements were obtained under optimal conditions, including: CCA concentration (0.05 mmol/L), pH (7), Edep (-0.3 V) tdep (60 s), AB concentration (0.5 mol/L), scan rate (150 mV/s), pulse height (80 mV), Hg drop size (4 mm 2 ) and linearity (Ip vs concentration), which was in the range from 5 to 170, 5 to 140 and 5 to 190 M, for Pb, Cd and Zn, respectively). The LOD (S/N = 3) values were 0.05, 0.03 and 0.05 µg/L for Pb, Cd and Zn, respectively. The repeatability and intermediate precisions were tested as RSD of 0.44, 1.21 and 1.23% for Pb, Cd and Zn, respectively. The recovery values were 98, 99 and 101% for Pb, Cd and Zn, respectively. As result, the DPAdSV method with CCA ligands was successfully applied for heavy metals determination in the seawater of a former bauxite mining area.