A novel electrochemical sensor for in situ and in vivo detection of sugars based on boronic acid-diol recognition

An ultrasensitive electrochemical sensor has been constructed to detect fructose and glucose in plants in situ and in vivo, employing boronic acid-diol recognition. The biosensor employed screen-printed electrode (SPE) as the substrate electrode, which was modified by nanocomposite of carboxylated graphene oxide-copper-based metal–organic frameworks (GO-COOH-Cu-MOFs), poly 3-aminophenylboronic acid (PAPBA) and Nafion. Detection of fructose or glucose was accomplished through electrochemical measurement of the peak current change of the combined peak of Cu2+ and boric acid. The detection range of Nafion/PAPBA/GO-COOH-Cu-MOFs/SPE sensor for fructose and glucose are 1 nM-1 M, and its detection limit is 0.065 nM and 0.085 nM, respectively. The sensor also exhibited excellent detection selectivity and stability. In addition, artificial neural networks (ANN) models were constructed to analyze responses from the sensor to enable intelligent and accurate analysis of fructose and glucose. The as-prepared sensor was also used to in situ and in vivo detection of sugar of tomato samples at different growth stages, confirming its great application potential in precision agriculture.