posted on 2024-02-01, 21:43authored byJiawei Zhu, Hao Yu, Caidie Chang, Boyi Liang, Qiang Li, Kai Dai, Changlong Jiang
Excessive
sulfite usage in food and pharmaceutical production causes
respiratory and neurological diseases, underscoring the need for a
sensitive and rapid quantification strategy. The portable sensing
platform based on a luminescent hydrogel sensor is a powerful tool
for the on-site, real-time detection of sulfite ions. However, the
lack of recyclability in almost all reaction-based hydrogel sensors
increases the application cost. This study constructed a reversible
and upconversion nanoprobe combining upconversion nanoparticles (UCNPs)
and pararosaniline (PAR) for sulfite detection. The upconversion nanoprobe
was further encapsulated in a three-dimensional polyacrylamide hydrogel
matrix to create a background-free, reversible hydrogel sensor. The
near-infrared excitation of UCNPs avoids the autofluorescence in the
hydrogel and real samples. Meanwhile, PAR serves as a specific recognition
unit for sulfite ions. After the addition of sulfites, a specific
reaction occurs between PAR and sulfites, leading to the recovery
of characteristic emission at 540 nm, achieving sensitive detection
of sulfite ions. Importantly, this specific reaction is reversible
under thermal treatment, allowing the hydrogel sensor to return to
its initial state and thus enabling reversible detection of sulfite
ions. Furthermore, a portable sensing platform is developed to realize
point-of-care, real-time quantitative detection of sulfite ions. The
proposed upconversion reversible hydrogel sensor provides a new sensing
strategy for the detection of hazardous substances in food and offers
new insights into the preparation of reversible, highly sensitive
hydrogel sensors.