Carbon nanotube sensor detects food dyes

By Joseph James Whitworth contact

- Last updated on GMT

Sunset Yellow and tartrazine are synthetic organic food dyes found in a variety of products
Sunset Yellow and tartrazine are synthetic organic food dyes found in a variety of products
A sensor that detects some synthetic organic food dyes has been created by Iranian researchers.

The team from Tabriz University developed and tested it on Sunset Yellow (SY) and Tartrazine (Tz) in food and beverage samples.

SY (known in Europe as E110) and Tz (E102 in Europe) were simultaneously determined on the carbon-ceramic electrode modified with carbon nanotube–ionic liquid (CNT–IL) nanocamposite.

Sunset Yellow and tartrazine are synthetic organic food dyes found in beverages, soft drinks, candies, dairy and bakery products. The presence and content of these dyes must be controlled due to their potential harm.

How it works

The sensor is made of carbon ceramic and modified with multi-walled carbon nanotube (CNT). Because bare carbon-ceramic electrodes have low detection sensitivity, modification was needed, said the researchers.

Ionic liquids (ILs) are organic salts or mixtures of salts that are fluid at room or near-room temperature.

Carbon-ceramic electrode modified with multiwalled carbon nanotubes–ionic liquid (MWCNTs–IL) nanocomposite was constructed and used for electrochemical determination of the chosen food dyes.

It was tested in soft drinks under optimized experimental conditions by the standard addition method.

Method comparison

Values were in agreement with those from high-performance liquid chromatography (HPLC).

The sensor has the advantages of carbon-ceramic composite electrodes (CCE) and benefitted from the carbon nanotubes and ionic Liquid, said the researchers.

“The proposed modified electrode can be easily constructed in a simple procedure, and the surface of electrode is also easily renewable. Also, the modified electrode shows high conductivity, promotion of fast electron transfer, and antifouling properties​,” they said.

The electrode behaved linearly to Sunset Yellow and tartrazine in the concentration range of 4×10−7 to 1.1×10−4M and 3×10−6 to 0.7×10−4M with a detection limit of 10−7M (0.045 mgL−1)and 1.1×10−6M (0.59 mgL−1), respectively.

Synthetic dyes are usually added to foodstuffs and soft drinks to improve appearance, color, and texture and maintain the natural color during process or storage.

Source: Food Analytical Methods, volume 6, issue 5, pages 1388-1897

Online ahead of print, DOI: 10.1007/s12161-012-9556-6

Carbon NanotubeIonic Liquid (CNTIL) Nanocamposite Modified Sol-Gel Derived Carbon-Ceramic Electrode for Simultaneous Determination of Sunset Yellow and Tartrazine in Food Samples”

Authors: Mir Reza Majidi,  Reza Fadakar Bajeh Baj, Abdolhossein Naseri

Related topics: R&D, Natural Colors & Flavors

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