# Aptamer-Based Biosensors for the Analytical Determination of Bisphenol A in Foodstuffs
([[https://echa.europa.eu/it/-/seven-new-substances-added-to-the-candidate-list-entry-for-bisphenol-a-updated-to-reflect-its-endocrine-disrupting-properties-for-the-environment](https://echa.europa.eu/it/-/seven-new-substances-added-to-the-candidate-list-entry-for-bisphenol-a-updated-to-reflect-its-endocrine-disrupting-properties-for-the-environment)]([https://echa.europa.eu/it/-/seven-new-substances-added-to-the-candidate-list-entry-for-bisphenol-a-updated-to-reflect-its-endocrine-disrupting-properties-for-the-environment](https://echa.europa.eu/it/-/seven-new-substances-added-to-the-candidate-list-entry-for-bisphenol-a-updated-to-reflect-its-endocrine-disrupting-properties-for-the-environment)); accessed on 15 January 2018) [20]. Due to limitations on the use of BPA, the plastic industry has selected BPA chemical analogs as substitutes for the manufacturing of FCMs. Bisphenol F (BPF), Bisphenol B (BPB) and Bisphenol S (BPS) are the most utilized ones (Figure 1). However, several studies have demonstrated that these compounds are as toxic as BPA; therefore, the safety of \"BPA-free\" materials is not effectively verified [21; 22; 23; 24; 25; 26; 27; 28; 29]. BPS is the only regulated substitute among BPA analogs. Regulation EU 10/2011 has indeed settled at 0.05 mg/kg of food as the  
Figure 1: Chemical structure of BPA and its analogs. SML for BPS [30]. Furthermore, the European Chemical Agency (ECHA) has begun the evaluation of BPB, BPF, and BPS as EDCs. In December 2021, following a re-evaluation of risks associated with exposure to BPA, the EFSA proposed to significantly lower the Tolerable Daily Intake (TDI) to 0.04 ng/kg bw/day for BPA. This decision was based on the analysis of studies published from 2013 to 2018, particularly those focusing on the adverse effects of BPA on the immune system ([[https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake](https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake)]([https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake](https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake)); accessed on 22 February 2022). For several years, some of the authors of the present review have been working on monitoring BPA and other bisphenols in different commonly used foods by means of LC-FD and LC-MS techniques [31; 32; 33; 34]. Generally, the determination of BPA in food is carried out by conventional analytical procedures consisting of a pre-treatment of samples using different extraction techniques, followed by a quali-quantitative analysis mainly by means of LC or GC chromatography, combined with a fluorescence detector or a mass spectrometer [35; 36]. However, these procedures are expensive and time-consuming. Furthermore, due to a recent EFSA decision ([[https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake](https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake)]([https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake](https://www.efsa.europa.eu/en/news/bisphenol-efsa-draft-opinion-proposes-lowering-tolerable-daily-intake)); accessed on 22 February 2022), the need of more sensitive and user-friendly methods for the quantitative analysis of these compounds in foodstuffs is imperative. In that context, the use of sensor technology, notably biosensors, can provide a suitable solution to this challenge [37]. According to the IUPAC definition, a biosensor is \"a device that uses specific biochemical reactions mediated by isolated enzymes, immunosystems, tissues, organelles or whole cells to detect chemical compounds usually by electrical, thermal or optical signals\" [38].