Development of amperometric lysine biosensors based on Au nanoparticles/multiwalled carbon nanotubes/polymers modified Au electrodes

Abstract

The construction of two amperometric l-lysine biosensors is described in this study. The construction comprises the covalent immobilization of lysine oxidase (LOx) onto nanocomposite composed of gold nanoparticles (AuNPs) and carboxylated multiwalled carbon nanotubes (c-MWCNT), decorated on (i) polyaniline (PANI) and (ii) poly 1,2 diaminobenzene (DAB), electrodeposited on Au electrodes. The biosensors were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and electrochemical impedance spectroscopy (EIS) studies. The optimum response (current) was observed within 2 s at pH 7.0 and 25 °C for LOx/AuNPs/c-MWCNT/PANI/Au, and 4 s at pH 7.0 and 30 °C for LOx/AuNPs/c-MWCNT/DAB/Au electrodes. There was a linear relationship between current and lysine concentration ranging from 5.0 to 600 μM for LOx/AuNPs/c-MWCNT/PANI/Au with a detection limit of 5.0 μM, and 20 to 600 μM for the LOx/AuNPs/c-MWCNT/DAB/Au electrode with a detection limit of 20 μM. The PANI modified electrode was in good agreement with the standard HPLC method, with a better correlation (r = 0.992) compared to the DAB modified electrode (r = 0.986). These observations revealed that the PANI modified Au electrode was better than the DAB modified electrode, and hence it was employed for the determination of lysine in milk, pharmaceutical tablets and sera. The PANI modified electrode showed a half life of 120 days, compared to that of 90 days for the DAB modified electrode, after their 100 uses, when stored at 4 °C.

Graphene/Poly(vinylferrocene) Composite Based Amperometric Biosensor for L‐lysine Determination

“…Some literature report a similar increase in the activity of the enzyme LyOx in weakly basic media and also emphasize higher electrode responses at higher pH values , . Different pH values such as 5.0 , 6.0 , 7.0 , , , 7.4 , , 7.5 , , 8.0 and 9.0 were also reported for lysine biosensors. However, it is important to highlight that the effect of pH on the biosensor response was not investigated in detail at pH values over 9.0.…”

“…In recent years there has been extensive work towards the development of biosensors because of their characteristics of rapid response, good selectivity, low cost, simple operation, high sensitivity and feasibility of miniaturization , . Various approaches have been made to develop potentiometric , , amperometric and optical , biosensing systems for L‐lysine determination. In L‐lysine biosensors L‐lysine dehydrogenase , L‐lysine‐2‐monooxygenase , L‐lysine‐decarboxylase and L‐lysine‐(α)‐oxidase enzymes have been used as biological recognition element for biosensor fabrication.…”

Development of Amperometric Glucose Biosensor Based on Prussian Blue Functionlized TiO2 Nanotube Arrays

“…The absorption band at 2089 cm −1 in PB/AuNP/TiNTs spectrum is a common characteristic of PB, corresponding to the stretching vibration of CN group. After depositing pDAB film onto PB/AuNP/TiNTs (curve ii), the bands at 3400 and 3185 cm −1 appear, which can be assigned to the strenching mode of N−H and NH 2 groups present in the polymer20. Besides, the presence of the bands at 1632 and 1503 cm −1 are belonged to the C = C stretching vibrations, and the band at 748 cm −1 is originated from the out of plane C−H bending vibration of the benzoid rings.…”

Selective Determination of Lysine in Dry-Cured Meats Using a Sensor Based on Lysine-α-Oxidase Immobilised on a Nylon Membrane

“…Cázares, Aristoy, Toldrá, 2011). Lysine has been analysed in several foods like cheese 91 and yoghurt (Ciriello et al, 2015), as well as in hydrolysate food like pasta and wheat 92 flour (Curulli et al, 1998;Divritsioti et al, 2003;Chauhan et al, 2012). The use of 93 lysine decarboxylase combined with diamine oxidase and the horseradish peroxidase 94 has been proposed for the analysis of free lysine in pet food (Bóka et al, 2015).…”