Development of a fluorescent probe for detecting Al3+ in cooked wheaten food based on phosphonic acid group functionalized polythiophene derivatives

As an unnecessary trace element, the content of aluminium in biological systems should be strictly controlled. Therefore, it was necessary to develop a convenient method for detection of aluminium ions. In this study, a fluorescent probe based on polythiophene derivatives was developed and used to detect Al3+ in Chinese traditional pasta. The fluorescence of this probe showed a significant decrease in hexamethylenetetramine–HCl buffer solution (pH 5) when Al3+ was present. In addition, the probe exhibited good sensitivity and selectivity to Al3+ over other metal ions when EDTA was used as the masking agent. Fluorescence intensity had a good linear relationship with the Al3+ concentration in the range 0.1–10 μM and the limit of detection for Al3+ was 39 nM. Furthermore, the probe was successfully applied to detect Al3+ in food samples and the results were consistent with ICP–AES. A fluorescent sensor based on polythiophene derivatives (PT‐BPPA) was used to detect Al3+. PT‐BPPA exhibited good sensitivity and selectivity to Al3+ in hexamethylenetetramine–HCl buffer solution (pH 5) and the limit of detection for Al3+ was 39 nM. This probe was applied successfully to detect Al3+ in food samples.