An Electrocatalytic Screen-Printed Amperometric Sensor for the Selective Measurement of Thiamine (Vitamin B1) in Food Supplements

Abstract

An electrocatalytic screen-printed sensor has been investigated for the measurement of the biologically important biomolecule vitamin B1 (thiamine) for the first time in food supplements. Under basic conditions, the vitamin was converted to its electrochemically active thiolate anion species. It was shown that an electrocatalytic oxidation reaction occurred with the screen-printed carbon electrode containing the mediator cobalt phthalocyanine (CoPC-SPCE). This had the advantage of producing an analytical response current at an operating potential of 0 V vs. Ag/AgCl compared to +0.34 V obtained with plain SPCEs. This resulted in improved selectivity and limit of detection. Detailed studies on the underlying mechanism occurring with the sensor are reported in this paper. A linear response was obtained between 0.1 and 20 µg mL−1, which was suitable for the quantification of the vitamin in two commercial products containing vitamin B1. The mean recovery for a multivitamin tablet with a declared content of 5 mg was 101% (coefficient of variation (CV) of 9.6%). A multivitamin drink, which had a much lower concentration of vitamin B1 (0.22 mg/100 mL), gave a mean recovery of 93.3% (CV 7.2%). These results indicate that our sensor holds promise for quality control of food supplements and other food types.

Pengembangan Deteksi Elektrokimia Tiamina Berbasis Elektrode Karbon Kaca Termodifikasi Pedot:pss Pada Suplemen Vitamin Komersial Menggunakan Teknik Differential Pulse Voltammetry

“…Menurut penelitian Hart et al, (1995), reaksi oksidasi tiamina tidak melibatkan proton sebagai penentu laju reaksi oksidasi, sehingga struktur yang menentukan laju reaksi oksidasi adalah anion tiolat. Puncak pertama merupakan puncak yang dihasilkan dari reaksi terbentuknya anion tiolat yang elektroaktif dari tiamina (Smart et al, 2019). Puncak voltammogram kedua selanjutnya dihasilkan dari reaksi oksidasi satu elektron anion tiolat (RS -) yang membentuk radikal (RS) yang kemudian dilanjutkan reaksi dimerisasi membentuk disulfida (RSSR) (Gambar 2).…”

Studies Towards the Development of a Novel, Screen-Printed Carbon-Based, Biosensor for the Measurement of Polyunsaturated Fatty Acids

“…Previous work by our group has demonstrated the feasibility of using SPCE sensors and (bio)sensors for the analysis of target analytes in challenging matrices for agri-food applications (progesterone in milk [11], monosodium glutamate in stock cubes [12], fructose in fruit juice [13], organophosphates in cereals and raw produce [14], boar taint in pork [15], thiamine in soft drinks [16]).…”