Optical microcavities, particularly whispering-gallery mode (WGM) microcavities, have been widely used as biosensors due to their high sensitivity to environmental changes. To enhance detection sensitivity to the single-molecule level, plasmonic nanorods are strategically placed on WGM microspheres to amplify the evanescent fields. This optoplasmonic approach enables the detection of single molecules, conformational changes, and even atomic ions, marking significant advancements in single-molecule sensing. This Perspective discusses the research prospects in optoplasmonic WGM sensing, including: 1. **Enzyme Thermodynamics and Kinetics**: Sensing conformational changes in active enzymes and their kinetics, as well as controlling enzyme synthesis thermodynamically. 2. **Thermo-Optoplasmonic Sensing**: Using optoplasmonic WGM for absorption spectroscopy, particularly for detecting forbidden optical transitions in proteins and amino acids. 3. **Synthetic Biology**: Applying optoplasmonic sensors to control enzymatic synthesis and monitor membrane proteins with high sensitivity. 4. **Sensing with Optoplasmonic Microlasers**: Utilizing microlasers for ultrasensitive single-molecule detection and in vivo applications. The combination of optoplasmonic WGM sensors with synthetic biology offers new opportunities for precise control of enzymatic processes and the synthesis of complex biopolymers, such as DNA. Additionally, optoplasmonic microlasers can enhance sensitivity and reduce background noise, making them suitable for in vivo sensing applications. Overall, optoplasmonic WGM sensing provides a promising avenue for advanced single-molecule studies and has potential applications in various scientific fields.Optical microcavities, particularly whispering-gallery mode (WGM) microcavities, have been widely used as biosensors due to their high sensitivity to environmental changes. To enhance detection sensitivity to the single-molecule level, plasmonic nanorods are strategically placed on WGM microspheres to amplify the evanescent fields. This optoplasmonic approach enables the detection of single molecules, conformational changes, and even atomic ions, marking significant advancements in single-molecule sensing. This Perspective discusses the research prospects in optoplasmonic WGM sensing, including: 1. **Enzyme Thermodynamics and Kinetics**: Sensing conformational changes in active enzymes and their kinetics, as well as controlling enzyme synthesis thermodynamically. 2. **Thermo-Optoplasmonic Sensing**: Using optoplasmonic WGM for absorption spectroscopy, particularly for detecting forbidden optical transitions in proteins and amino acids. 3. **Synthetic Biology**: Applying optoplasmonic sensors to control enzymatic synthesis and monitor membrane proteins with high sensitivity. 4. **Sensing with Optoplasmonic Microlasers**: Utilizing microlasers for ultrasensitive single-molecule detection and in vivo applications. The combination of optoplasmonic WGM sensors with synthetic biology offers new opportunities for precise control of enzymatic processes and the synthesis of complex biopolymers, such as DNA. Additionally, optoplasmonic microlasers can enhance sensitivity and reduce background noise, making them suitable for in vivo sensing applications. Overall, optoplasmonic WGM sensing provides a promising avenue for advanced single-molecule studies and has potential applications in various scientific fields.