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.
Highlights
The above results exhibit that the PPRONPs–Carbon dots (CDs) and Multiwalled carbon nanotubes (MWCNTs) can significantly impact the peak current of Indole-3-acetic acid (IAA) and salicylic acid (SA)
IAA and SA are two common phytohormones that play an important role in plant growth and development, ripening, etc.; it is necessary to simultaneously detect the two phytohormones
A novel PPRONPs–CDs–MWCNTs composite was prepared by facile hydrothermal reaction and ultrasonic treatment for IAA
Summary
Developing an effective method for sensitive simultaneous detection of phytohormones remains a challenge. Carbon dots (CDs) are novel zero-dimensional carbon nanomaterials Because of their unique fluorescent properties, good biocompatibility and water solubility, small quantum size, low toxicity, and low raw material cost, they have been widely used in many fields, such as medical imaging [18–20], luminescence detection [21], electrochemical detection [22], etc. ‘Amino acid polymers’ is a collective term for a class of polymers connected by amino acid monomers or their derivatives through amide bonds [23] They have a stable secondary structure similar to that of natural proteins, excellent biocompatibility, biodegradability, and functional groups with diverse side chain structures. A novel composite consisting of poly(L-Proline) nanoparticles (PPRONPs), CDs, and MWCNTs is facilely prepared by a hydrothermal reaction and ultrasonic treatment for simultaneous amperometric detection of IAA and SA. The proposed sensor was found to exhibit good analytical properties (sensitivity, low detection limit) for IAA and SA detection
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
