Flexible Screen Printed Aptasensor for Rapid Detection of Furaneol: A Comparison of CNTs and AgNPs Effect on Aptasensor Performance

Abstract

Furaneol is a widely used flavoring agent, which can be naturally found in different products, such as strawberries or thermally processed foods. This is why it is extremely important to detect furaneol in the food industry using ultra-sensitive, stable, and selective sensors. In this context, electrochemical biosensors are particularly attractive as they provide a cheap and reliable alternative measurement device. Carbon nanotubes (CNTs) and silver nanoparticles (AgNPs) have been extensively investigated as suitable materials to effectively increase the sensitivity of the biosensors. However, a comparison of the performance of biosensors employing CNTs and AgNPs is still missing. Herein, the effect of CNTs and AgNPs on the biosensor performance has been thoughtfully analyzed. Therefore, disposable flexible and screen printed electrochemical aptasensor modified with CNTs (CNT-ME), or AgNPs (AgNP-ME) have been developed. Under optimized conditions, CNT-MEs showed better performance compared to AgNP-ME, yielding a linear range of detection over a dynamic concentration range of 1 fM–35 μM and 2 pM–200 nM, respectively, as well as high selectivity towards furaneol. Finally, our aptasensor was tested in a real sample (strawberry) and validated with high-performance liquid chromatography (HPLC), showing that it could find an application in the food industry.

An Aptasensor Based on a Flexible Screen-Printed Silver Electrode for the Rapid Detection of Chlorpyrifos

“…Another effective method for further characterization of an electrode’s surface feature is EIS, from which the Nyquist diagrams are derived [ 58 ]. To explain the impedance output and to relate the biological to the electrical domain, the Randles equivalent circuit (inset of Figure 3 B) was used.…”

Flexible Screen-Printed Electrochemical Sensors Functionalized with Electrodeposited Copper for Nitrate Detection in Water

“…To evaluate the nature of the NO 3 – electrochemical reaction of screen-printed Cu/Ag electrodes, the effect of the scan rate (50 to 500 mV s –1 ) on the reduction peak current was investigated, as shown in Figure A. The cathodic peak current increased linearly with the increase of the scan rate (Figure B), suggesting a diffusion-controlled reduction process as described by the Randles-Sevcik eq where i p is the peak current, n is the number of electron transfers (here it is 2 for NO 3 – ), α is the cathodic electron transfer coefficient, A is the active surface area (cm 2 ), D o is the diffusion coefficient (2.0 × 10 –6 cm 2 s –1 for NO 3 – ), v is the scan rate (V s –1 ), and C is the NO 3 – concentration (mol cm –3 ). On the contrary, the potential ( E p ) at which the NO 3 – reduction occurs shifted negatively with the increment of scan rate as shown in Figure S4A.…”

Recent Advances in Aptamer Sensors

“…Another technique is based on the increase in charge transfer resistance via the impedance technique [ 174 ]. Therefore, an electrochemical aptasensor was provided for the detection of several targets, such as ampicillin (AMP), avian influenza virus (H5N1), carbohydrate antigen 125, Pb 2+ , lysozymes, insulin, thrombin, CD44, vanillin, circulating human MDA-MB-231 breast cancer cells, bisphenol A, furaneol, and Hg 2+ , among others [ 8 , 46 , 175 , 176 , 177 , 178 , 179 , 180 , 181 , 182 , 183 , 184 , 185 , 186 , 187 , 188 , 189 ].…”