A new water-soluble polythiophene derivative as a probe for real-time monitoring adenosine 5'-triphosphatase activity in lysosome of living cells

Detection of the adenosine 5'-triphosphatase (ATPase) activity in lysosome of living cells is of great importance for clinical diagnosis of many related diseases, including Cancer. In this work, a new water-soluble polythiophene derivative named ZnPT bearing both quaternary ammonium salt groups and dipicolylamine-Zn²⁺ (DPA-Zn²⁺) complexes in its side chain, was designed and synthesized for this propose. The probe mainly localized to lysosome with good biocompatibility and membrane penetration. The real-time, continuous, direct, and label-free assays were achieved through a fluorescence "turn-on" mode by taking advantages of the reaction specificity of ATPase with ATP and the high binding selectivity of ZnPT toward ATP substrate over its hydrolysis product (ADP). This well designed strategy should provide a facile and effective way for investigating ATPase-relevant biological processes.

ATPase activity assay; Cell imaging; Fluorescent probes; Multisite-binding; Polythiophene.