Molecularly Imprinted Polymer‐Based Electrochemical Sensor for In Situ Detection of Free Proline in Cucumber Leaves

Abstract

Proline is an important amino acid, which is crucial to plant growth and development. Accurate analysis of proline content is of great significance for understanding its physiological mechanism in plants. In this paper, according to the requirements for in‐situ detection in plants in precision agriculture, an electrochemical molecular imprinted polymers (MIP) sensor for determining proline in living plants was developed. Polypyrrole (PPy) was used as the functional monomer. To improve the performance of the MIP sensor, Au nanoparticles (NPs) were electrodeposited on the screen‐printed electrodes (SPEs) electrode. Thionine (Thi) was then electropolymerized on the SPEs to be used as an internal reference signal molecule. The MIP‐based proline sensor has the widest detection range of 1×10−16 −0.01 M. And its detection limit is the lowest (9.18 aM) so far. It was also used for measuring free proline in the leaves of living cucumber seedlings under salt stress. The MIP‐based proline sensor has an important prospect for detecting the physiological status of plants in situ and will play an important role in smart agriculture.

A mesothelin microsensor based on an embedded thionine electronic medium within an imprinted polymer on an acupuncture needle electrode

“…14 Yan et al prepared an electrochemical MIP sensor using thionine as an internal reference signal to determine proline. 15 Liu et al used polythionine as an imprinting polymer and an internal reference signal to specifically detect Pb 2+ . 16 Acupuncture needles (ANs) are traditionally medical implements that have been developed as novel microelectrodes due to their small size, fine tips, suitable mechanical strength, and electrical conductivity.…”