Rational design of ultrahigh sensitive sunset yellow sensor based on 3D hierarchical porous graphitic carbon with sub-nanopores

The content of sunset yellow (SY) in food must be strictly controlled, because its excessive intake may cause many adverse health effects. Herein, we proposed an ultrasensitive SY sensor by using hierarchical porous graphitic (HPG) carbon derived from polyaniline hydrogel. After a first step of polymerization, the HPG carbon was prepared through carbonization and further chemical activation. In particular, the activation process endowed the HPG carbon with a high content of optimized porous architecture (sub-nanoporous surface area accounts for more than 90% of microporous surface area), and thus providing a structural basis for high efficiency of SY pre-concentration on HPG carbon surface. Therefore, the proposed sensor showed record-high sensitivity (5285.7 A M −1 cm −2 ) and ultra-low detection limit (0.15 nM), which represents a performance improvement in SY sensing. Furthermore, the sensor displays excellent selectivity, reproducibility and stability, exhibiting a great perspective in ultrasensitive monitoring of SY in commercial products.