Novel SeS2-loaded Co MOF with Au@PANI comprised electroanalytical molecularly imprinted polymer-based disposable sensor for patulin mycotoxin

An SeS2-loaded Co MOF and Au@PANI nanocomposite comprising the base matrix of the electrode was developed with electropolymerized molecularly imprinted polymer (MIP) consisting of p-aminobenzoic acid (PABA) and patulin (PT) to detect PT molecules based on the PT imprinted cavities. SeS2@Co MOF and Au@PANI were synthesized using hydrothermal synthesis and interfacial polymerization strategies, respectively. A suitable functional monomer to fabricate the MIP platform was selected using the density functional theory (DFT/M06-2X method). Higher electrochemical active surface area (0.985 cm2 which is 6.99 times higher than the bare SPE) and a lower charge transfer resistance (Rct = 27.8 Ω) at the MIP/Au@PANI/SeS2@Co MOF electrode was achieved based on the higher number of adsorptive sites and enhanced conductivity (electron transfer rate constant (ks = 3.24 × 10−3 s−1) of the sensing platform. The fabricated MIP sensor performance was studied in 10 mM PBS (pH = 6.4), where an improved detection limit (0.66 pM) for PT and a broad logarithmic linear dynamic range (0.001–100 nM) were both observed. The sensor possessed higher selectivity (Imprinting factor = 15.4 for PT), excellent reusability (%RSD of 10 cycles = 2.49%), high storage stability (6.7% lost after 35 days), and robust reproducibility (%RSD = 3.22%) The as-prepared MIP-based PT sensor was applied to detect PT in a real-time apple juice sample (10% diluted with PBS) with a recovery % ranging from 94.5 to 106.4%. The proposed sensor possesses great advantages in terms of cost-effectiveness, providing a simple detection strategy for long-term storage stability, and reversible cycle measurements. [Display omitted] •A novel SeS2 incorporated Co MOF and Au@PANI nanocomposite was developed.•PABA was optimized as a suitable functional monomer based on the density functional theory.•The developed MIP exhibited a large number of PT binding sites with higher binding energy.•Au@PANI/SeS2@Co MOF generated an excellent electrochemical response.•The sensor shows excellent selectivity, long-term stability and reversible behavior.