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

Abstract

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.

Graphitic Carbon Nitride Nanosheets Decorated with Strontium Tungstate Nanospheres as an Electrochemical Transducer for Sulfamethazine Sensing

“…In addition, the interfering molecule’s oxidation potential varied from the SMZ oxidation range. So this could not influence the SMZ oxidation current density. , …”

Amino-Functionalized Hierarchical Porous Carbon Derived from Zeolitic Imidazolate Frameworks for Ultrasensitive Electrochemical Sensing of Heavy Metals in Water

“…The DPSV peak currents of the three HMIs increase fast when the deposition potential is decreased from −1.0 to −1.3 V due to the enhanced reduction of HMIs. However, because the evolved hydrogen can suppress the adsorption of HMIs to the electrode by invoking the steric hindrance effect, 54 the peak currents keep constant as the deposition potential is further decreased. The deposition time determines the amount of metal species, and thus affects the current response towards HMIs.…”

Recent advances in the modification of electrodes for trace metal analysis: a review

“…NMs have been primarily applied on the electrodes in combination with other modifiers (including through the formation of composites). [22][23][24][25]27,[30][31][32]34,46,47,50,54,59,67,70,72,75,83,85,86,88,89,[92][93][94][95][96][97][98][99][100][101][102]107,113,115,117,118,[122][123][124][125][126][129][130][131]135,136,[138][139]...…”

“…32,98,101,142,148,154,158 However, the use of CNTs also faces challenges related to their synthesis (i.e., cost and specific route) as well as the need for binders to improve their mechanical stability. 196 Metals (i.e., Ag, Au, Bi, Pd, Pt, Pb, and Sn), [23][24][25]56,57 27,31,67,96,100,103,109,112,118,122,124,130,131,133,[135][136][137]188,197,198 are the most commonly used NPs in the modification of the electrodes. In addition, clinoptilolite (a naturally occurring zeolite containing Si and Al) NPs were ion exchanged in a Fe(II) solution, and the modified CPE obtained was used in the determination of Sn 2+ .…”

“…2 presents the preparation of magnetic NiFe 2 O 4 -NPs and polypyrrole (PPy) nanocomposites used in the modification of a GCE for the determination of Pb 2+ in tap, lake, and river water samples. 96 Although the performance of the NM-modified electrodes has been mainly tested in real water samples, several studies reported on their use in heavy metal determination in other samples, including, among others, body fluids 31,57,88,163,173,190 and cosmetic product 190 samples. Moreover, Das et al 31 successfully employed a bimetal oxide (Bi 2 O 3 /Fe 2 O 3 )-NP decorated GO modified PGE for the determination of Cd 2+ in a wide range of real samples, including food (potato, lemon, and apple), soil, biological samples (blood serum and urine), and water (tap, drinking and chemical laboratory wastewater) samples.…”