A sperm cell-based biosensor using fluorescence probe for responsive signal readout towards bitter detection

Abstract

Bitter detection has attracted extensive attention in industries and basic researches due to pharmacological and/or food safety issues. Bitter receptor is a kind of G protein-coupled receptors (GPCRs), the research finds that the mice sperm cells contain slot of bitter taste gene expression. When the GPCR is activated by bitter compounds, a series of cascade reactions can lead to the changes in intracellular calcium concentration. In addition, the intracellular calcium concentration changes can be detected using the specific fluorescence probe. Based on the mechanisms mentioned above, this study proposes a novel biosensor that utilized sperm cell as primary sensing element, and employed Fluo4-AM and flow cytometry to measure the concentration changes of intracellular calcium ions for the detection of bitter compounds. Three bitter compounds were investigated by analyzing the responsive fluorescent intensity changes under various concentrations. Furthermore, the responses of this biosensor to five basic flavors were examined to evaluate the specificity of this bitter biosensor. The results revealed that this bitter biosensor could respond to bitter compounds in a dose-dependent manner with high specificity. This biosensor may provide a promising approach for detecting various bitter compounds.