Manganese cobalt-MOF@carbon nanofiber-based non-enzymatic histamine sensor for the determination of food freshness

Early detection of histamine in foodstuffs/beverages could be useful in preventing various diseases. In this work, we have prepared a free-standing hybrid mat based on manganese cobalt (2-methylimodazole)-metal organic frameworks (Mn-Co(2-MeIm)MOF) and carbon nanofibers (CNFs) and explored as a non-enzymatic electrochemical sensor for determining the freshness of fish and bananas based on histamine estimation. As-developed hybrid mat possesses high porosity with a large specific surface area and excellent hydrophilicity those allow easy access of analyte molecules to the redox-active metal sites of MOF. Furthermore, the multiple functional groups of the MOF matrix can act as active adsorption sites for catalysis. The Mn-Co(2-MeIm)MOF@CNF mat-modified GC electrode demonstrated excellent electrocatalytic activities toward the oxidation of histamine under acidic conditions (pH = 5.0) with a faster electron transfer kinetics and superior fouling resistance. The Co(2-MeIm)MOF@CNF/GCE sensor exhibited a wide linear range from 10 to 1500 mu M with a low limit of detection (LOD) of 89.6 nM and a high sensitivity of 107.3 mu A mM(-1) cm(-2). Importantly, as-developed Nb(BTC)MOF@CNF/GCE sensor is enabled to detect histamine in fish and banana samples stored for different periods of time, which thus indicates its practical viability as analytical histamine detector.

Automated summary

In this study, a hybrid array based on manganese cobalt (2-methylimodazole)-metal organic frameworks (Mn-Co(2-MeIm)MOF) and carbon nanofibers (CNFs) was prepared as a non-enzymatic electrochemical sensor for histamine detection in fish and bananas. The hybrid array exhibited high porosity, large specific surface area, and excellent hydrophilicity, enabling easy access of analyte molecules to the redox-active metal sites of the MOF. The sensor demonstrated excellent electrocatalytic activity for histamine oxidation under acidic conditions, with a wide linear range, low limit of detection, and high sensitivity. Importantly, the sensor was capable of detecting histamine in fish and banana samples stored for different periods of time, indicating its practical viability as an analytical histamine detector.