An Upconversion Luminescence Nanoprobe for the Ultrasensitive Detection of Hyaluronidase

A new upconversion luminescence nanoprobe for the detection of hyaluronidase has been developed by coupling the hyaltronic acid;bearing up conversion fluorescence nanoparticles (HA-UCNPs) with poly(in-phenylenediamine) (PMPD) nanospheres via covalent linkage. The nanoprobe alone exhibits an extremely low background signal owing to the effective fluorescence quenching by electron rich PMPD and the neat-infrared excitation characteristic (lambda(ex) = 986 nm), of HA-UCNPs; upon reaction With hyaluronidase; however, a more than 31-fold fluorescence enhancement is produced. Compared with the corresponding nanosystem assembled via physical adsorption, the prepared nanoprobe Shows a largely increased,stability and a much :higher signal-to-background ratio, which offers arm ultrasensitive, assay for hyalurornidase, with a detection limit of 0.6 ng/mL, The nanoprobe has been successfully used to determine hyaluronidase in human serum samples from both colorectal cancer patients and healthy people, disclosing that the serum hyaluronidase level in colorectal cancer patients is roughly 3 times, higher than that in healthy people. Furthermore, the nanoprobe also been employed to study the activity change of hyaluronidase affected by different concentrations of arsenate (a potential carcinogen), and the results show that even a low dosage of arsenate (50 mu g/L) can raise the activity of hyaluronidase by about one-third, revealing the relationship between arsenate and the enzyme The proposed method is not only simple but also highly sensitive, Making it useful to assay hyaluronidase in relevant clinical samples.