Disposable Amperometric Biosensor Based on Poly‐L‐lysine and Fe₃O₄ NPs‐chitosan Composite for the Detection of Tyramine in Cheese

Abstract

An amperometric tyramine biosensor based on poly‐L‐lysine (PLL) and Fe3O4 nanoparticles (Fe3O4NP) modified screen printed carbon electrode (SPCE) was developed. PLL was formed on the SPCE by the electropolymerization of L‐lysine. Subsequently, Fe3O4NP suspension prepared in chitosan (CH) solution was casted onto the PLL/SPCE. Tyrosinase (Ty) enzyme was immobilized onto the modified Fe3O4−CH/PLL/SPCE and the electrode was coated with Nafion to fabricate the Ty/Fe3O4−CH/PLL/SPCE. Different techniques including scanning electron microscopy, chronoamperometry (i–t curve), cyclic voltammetry and electrochemical impedance spectroscopy were utilized to study the fabrication processes, electrochemical characteristics and performance parameters of the biosensor. The analytical performance of the tyramine biosensor was evaluated with respect to linear range, sensitivity, limit of detection, repeatability and reproducibility. The response of the biosensor to tyramine was linear between 4.9×10−7–6.3×10−5 M with a detection limit of 7.5×10−8 M and sensitivity of 71.36 μA mM−1 (595 μA mM−1 cm−2). The application of the developed biosensor for the determination of tyramine was successfully tested in cheese sample and mean analytical recovery of added tyramine in cheese extract was calculated as 101.2±2.1 %. The presented tyramine biosensor is a promising approach for tyramine analysis in real samples due to its high sensitivity, rapid response and easy fabrication.

Graphene Quantum Dot‐poly(L‐lysine)‐gold Nanoparticles Nanocomposite for Electrochemical Determination of Dopamine and Serotonin

“…Then, the GQD solution was dispersed in the L‐Lys solution at a concentration of 0.5 mg/mL, and the obtained L‐Lys‐GQD solution was ultrasonically mixed for an hour. After that, the one‐step electrodeposition of L‐Lys‐GQD was performed onto PGE/AuNPs electrode in the potential range between −1.1 V and 2.2 V for seven cycles at 50 mV/s [31]. The resulted electrode was referred to as PGE/AuNps/P(L‐Lys)‐GQD.…”

Screen-Printed Electrode-Based Sensors for Food Spoilage Control: Bacteria and Biogenic Amines Detection

“…The use of nanomaterials is also frequent: single or multi-walled carbon nanotubes [ 104 , 109 ], graphene [ 108 ], nanoparticles [ 110 , 111 , 114 , 116 ], or the combination of different kind of nanomaterials [ 105 ]. An example is the sensor developed by Pérez et al [ 104 ] that combines the use of two enzymes, DAO and horseradish peroxidase (HRP), with MWCNT and ferrocene as mediator.…”

Folding-Based Electrochemical Aptasensor for the Determination of β-Lactoglobulin on Poly-L-Lysine Modified Graphite Electrodes

“…The modification of the GSPEs was monitored by cyclic voltammetry, dropping 50 µL of the redox probe [Fe(CN) 6 ] 4−/3− (equimolar solutions of 5.0 mM in 0.1 M KCl). The potential was cycled from -0.4 V to +0.8 V using different scan rates (25,50,75,100,125, and 150 mV·s −1 ). The intensity of the current (i p , A) was measured and plotted against the square root of the scan rate (ν, V·s −1 ), showing a linear behaviour.…”

“…The modification was evaluated in all the steps of the modification using cyclic voltammetry at different scan rates (25,50,75,100,125, and 150 mV·s −1 ) using the redox probe ferro/ferricyanide ([Fe(CN) 6 ] 4−/3− ).…”

“…Considerably different conducting polymers have been stated [45], and polyaniline (PANI) [46], polyacetylene [47], polypyrrole (PPy) [48], and poly(3,4-ethylenedioxythiophene) (PEDOT) [49] are among the most widely used. Apart from them, another polymer that has attracted attention is poly-L-lysine (PLL), due to its versatility, good biocompatibility, stability, and good solubility in water [50,51]. It can be quickly prepared by the electropolymerization of L-lysine, an essential amino acid usually employed in protein biosynthesis [52].…”