Remote Magnetically Oriented Xanthan-Biochar Microtube-Fe۳O۴-Molecularly Imprinted Biopolymer Hydrogel toward Electrochemical Enantioselection of L-Tryptophan

L-Tryptophan is known as a vital biological amino acid associated with metabolism and protein synthesis precursor and deficiency and its abundance leads to a decrease in neurotransmitters andneurological diseases [۱]. Currently, developing portable electrochemical sensors for monitoring and enantioselection of tryptophan is a hot topic, and there are significant challenges [۲]. Hydrogels with polymeric networks can be applied as a medium to realize solid-state sensing. However, it is still a hard task to enable hydrogel to simultaneously possess effective mass transfer, mechanicalrobustness as well as easy and tight adhesion to sensing electrodes. Routinely, a hydrogel with improved adhesion to the electrode surface by introducing additives may deteriorate the mass transfer capability [۳]. Increasing the porosity of hydrogel could enhance mass diffusion butsacrifices mechanical robustness. Herein, we developed a remote magnetically oriented xanthanbiochar microtube (derived from Loofah)-Fe۳O۴-molecularly imprinted polydopamine hydrogel and applied it as an electrochemical enantioselective sensor for the L-tryptophan recognition. The physicochemical and electrochemical characterization results confirm the successful synthesis ofas-proposed materials. The operational factors such as pH, response time, loading sample volume and loading active materials mass were optimized and at optimization condition, the affordable linear range (۰.۰۰۵-۵۰۰μM) and desirable limit of detection (۱.۵nM) were founded. Additionally, the proposed electrochemical sensor showed good reproducibility, and desirable selectivitytowards the determination of L-Try, which makes it suitable for the analysis of L-Try in humanplasma and serum samples. It paves an attractive, accessible, and effective strategy to on-site evaluate L-Trp level for forewarning healthcare monitoring.