Ultrasensitive molecularly imprinted electrochemical sensor for in situ determination of serine in plants

Serine (SER) is a functional amino acid that promotes plant growth and development, and plays an important role in plant stress response. In this paper, an ultrasensitive electrochemical sensor based on molecularly imprinted method (MIP) has been constructed to detect SER in plants in situ and in vivo. Composite material of titanium carbide (MXene), zeolitic imidazolate frameworks (ZIF-8) and thionin (Thi) was used to improve the conductivity and electroactive area of the sensor. Dopamine (DA) was used as the functional monomer to form the MIP. The prepared MIP/Thi-ZIF-8-MXene/SPE sensor showed an ultra-sensitive SER detection response with a detection range of 1 nM-4 mM (R² = 0.995) and a detection limit of 0.69 nM (S/N = 3). It was also used to detect free SER in lettuce leaves under salt stress, which verified the practicality of the sensor. The MIP-based SER sensor has important application prospects for detecting the physiological status of plants in situ.