A dual-site controlled pH probe revealing the pH of sperm cytoplasm and screening for healthy spermatozoa.

A dual-site controlled pH probe, which is composed of gold nanoparticles and modified with rhodamine and fluorescein derivatives, was applied to sensitively monitor intracellular pH changes in sperm. The pH probe revealed the intracellular pH of sperm under different conditions and demonstrated the lower pH in asthenozoospermia patients as compared to healthy individuals. Importantly, the pH probe can help screen for healthy sperm.