This study demonstrates the possibility of a microcavity array-based bioreactor to investigate intracellular sodium changes using sodium TQ signal. The response of HepG2 cells during 60min Na+/K+-ATPase inhibition by 1mM ouabain or K+-free medium was monitored. An improved TQTPPI sequence with almost four times TQ SNR increase allowed achieving cell sensitivity of 14*106. During cell experiments, the TQ signal increased to 128.9±3.9% and 165.0±7.4% for 1mM ouabain and K+-free medium, respectively. After reperfusion, the TQ signal recovered to 129.5±4.5%. This bioreactor design with improved TQ signal detection provides the capability to investigate a variety of cells using sodium TQ signal.