Fluorescent indicators for live-cell and in vitro detection of inorganic cadmium dynamics

Abstract

Cadmium contamination is a severe threat to the environment and food safety. Thus, there is an urgent need to develop highly sensitive and selective cadmium detection tools. The engineered uorescent indicator is a powerful tool for the rapid detection of inorganic cadmium in the environment. In this study, the development of yellow uorescent indicators of cadmium chloride by inserting a uorescent protein at different positions of the high cadmium-speci c repressor and optimizing the exible linker between the connection points is reported. These indicators provide a fast, sensitive, speci c, high dynamic range, and real-time readout of cadmium ion dynamics in solution. Under optimal conditions, the uorescent indicators N0C0/N1C1 showed a linear response to cadmium concentration within the range from 10/30 to 50/100 nM and with a detection limit of 10/33 nM. Escherichia coli cells containing the indicator were used to further study the response of cadmium ion concentration in living cells. E. coli N1C1 could respond to different concentrations of cadmium ions. This study provides a rapid and straightforward method for cadmium ion detection in vitro and the potential for biological imaging.

Development of the IMP biosensor for rapid and stable analysis of IMP concentrations in fermentation broth

“…Continuing our optimization based on the dIMPDHΔBateman‐320/324 sensors, it has been reported in the literature that deletion of the first protein Met [ 37 ] of cpYFP can greatly improve the response value of the cpFP sensor. The deletion of the first protein Met of cpYFP in dIMPDHΔBateman‐320/324 did improve the response value of the cpFP sensor a little bit compared to the original sensor, but not significantly (Figure 2A).…”