Colorimetric and fluorescent probe for dual-response to pH values, and viscosity: Applications in cellular imaging and food safety

A colorimetric and fluorescent probe LDN was constructed for detecting pH values and viscosity. • LDN was mainly distributed in lysosomes and showed an excellent lysosome-targeting effect. • LDN could present significant fluorescence enhancement in living cancer cells. • LDN has been effectively utilized to verify the feasibility of detecting the spoilage of milk. Detecting the fluctuations in viscosity and pH values simultaneously at the molecular level holds significance for monitoring the spoilage processes of liquid food to ensure food safety. Also, viscosity and pH value can be regarded as effective cancer markers for diagnosis. Therefore, we successfully engineered and fabricated a colorimetric and fluorescent probe LDN for detecting pH values and viscosity. As the pH value varies, LDN exhibits different fluorescence emission wavelengths. Across a viscosity spectrum from 1.5 cP to 312.84 cP, a quantifiable relationship exists between fluorescence signal intensity and viscosity. Probe LDN, with lyso-targeting characteristics, shows significant fluorescence enhancement in living cancer cells. Furthermore, its utility extends to the surveillance of food degradation, particularly within acidic matrices such as milk. These findings underscore the significant potential of LDN in imaging tumor cells and monitoring food spoilage processes, offering a promising possibility for enhancing food safety assurance. Download: Download high-res image (61KB) Download: Download full-size image