Simultaneous Electrochemical Sensing of Indole-3-Acetic Acid and Salicylic Acid on Poly(L-Proline) Nanoparticles–Carbon Dots–Multiwalled Carbon Nanotubes Composite-Modified Electrode

Abstract

Sensitive simultaneous electrochemical sensing of phytohormones indole-3-acetic acid and salicylic acid based on a novel poly(L-Proline) nanoparticles–carbon dots composite consisting of multiwalled carbon nanotubes was reported in this study. The poly(L-Proline) nanoparticles–carbon dots composite was facilely prepared by the hydrothermal method, and L-Proline was used as a monomer and carbon source for the preparation of poly(L-Proline) nanoparticles and carbon dots, respectively. Then, the poly(L-Proline) nanoparticles–carbon dots–multiwalled carbon nanotubes composite was prepared by ultrasonic mixing of poly(L-Proline) nanoparticles–carbon dots composite dispersion and multiwalled carbon nanotubes. Scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, energy dispersive spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry were used to characterize the properties of the composite. poly(L-Proline) nanoparticles were found to significantly enhance the conductivity and sensing performance of the composite. Under optimal conditions, the composite-modified electrode exhibited a wide linear range from 0.05 to 25 μM for indole-3-acetic acid and from 0.2 to 60 μM for salicylic acid with detection limits of 0.007 μM and 0.1 μM (S/N = 3), respectively. In addition, the proposed sensor was also applied to simultaneously test indole-3-acetic acid and salicylic acid in real leaf samples with satisfactory recovery.

Portable Electrochemical Sensing of Indole‐3‐acetic Acid Based on Self‐assembled MXene and Multi‐walled Carbon Nanotubes Composite Modified Screen‐printed Electrode

“…Therefore, IAA undertakes an irreversible oxidation reaction on the surface of MXene‐MWCNTs/SPE with two electrons and one hydrogen involved, and the oxidation mechanism is expressed in Figure 5 [40].…”

Recent trends in nanostructured carbon-based electrochemical sensors for the detection and remediation of persistent toxic substances in real-time analysis

“…The abundance of oxygen-containing moieties upon the substrates of CDs and GDs especially renders them an advantageous electrochemical sensor. According to Li et al [119] a unique composite comprised of MWCNTs and poly(L-Proline) NPs called poly(L-Proline) NPs-CDs allows for the sensitive combined electrochemical detection of the phytohormones indole-3-acetic acid and salicylic acid. In this research, 0.69 g of Pro was dissolved in 10 ml of HAuCl 4 media (8 mM) while vigorously mixing, and the resulting media was then added to a reaction vessel that was warmed in a microwave for 11 h at 160 C. To produce the PPRONPs-CDs composite dispersed, the specimen was removed following the hydrothermal process and deionized using a 3500D dialysis bag for 24 h. Under identical conditions, CDs made from Pro without HAuCl 4 were created.…”

“…Employing a pipette, 4 l of ink was put over the GCE. The ink was allowed to drip-dry in the air, and the PPRONPs-CDs-MWCNTs/GCE was acquired for the subsequent sensing (see figure 10) [119].…”

Water Soluble PMPC-Derived Bright Fluorescent Nitrogen/Phosphorous-Doped Carbon Dots for Fluorescent Ink (Anti-Counterfeiting) and Cellular Multicolor Imaging

“…Recently much effort has been made in the preparation of CDs from biowaste [ 30 , 31 ] and plant sources [ 32 , 33 ]. Apart from the small molecules, polymers are employed as carbon sources for the synthesis of CDs [ 34 , 35 , 36 , 37 , 38 , 39 ]. Any functional group that is present in small molecules or polymers will be retained as surface functional groups in CDs [ 40 , 41 , 42 ].…”