The use of coated glass substrates for signal enhancement in multiphoton imaging

In nonlinear optical imaging of biological samples, epi-illumination collection of fluorescent signals results in half of the signal loss. We enhanced the collected luminescent signal by using a multilayer coating of tantalum pentoxide (Ta2O5) and cerium oxide (SiO2). Our coatings are biocompatible, allowing visual inspection of samples and optimizing the collection of luminescent signals. This method was confirmed on a number of samples, including sulforhodamine solutions, fluorescent microspheres and labeled 3T3 cells. In all cases, the coated coverslips were used to enhance the signal by approximately 2 times. Image analysis also shows that signal enhancement does not result in additional photobleaching. Our results indicate that the designed coated coverslip enhances multi-photon microscopy detection signals.