Enzyme-encapsulated metal-organic framework ZIF-8-mediated biosensor for ultrasensitive detection of urinary prostatic exosomal protein using a glucose meter.

A highly sensitive and efficient home-use method is impressive and promising in the self-monitoring of chronic prostatitis (CP). Herein, we developed a glucose oxidase-zeolitic imidazolate framework-8-antibody composite (GOx@ZIF-8@Ab2) to achieve highly sensitive point-of-care testing (POCT) of urinary prostatic exosomal protein (PSEP) by combining it with a personal glucometer (PGM). The developed GOx@ZIF-8@Ab2 was prepared through a simple but effective biomineralization reaction and a strong binding affinity between Zn2+ and Fc region of the antibody. This bifunctional material GOx@ZIF-8@Ab2 could not only specifically recognize the PSEP via immunoreaction but also wrap a large number of GOx molecules. Following the sandwich immunoreaction, the prepared GOx@ZIF-8@Ab2 facilitated hydrolysis of glucose in a one-to-many fashion, amplifying the detection signal and greatly improving the sensitivity of PGM detection. In comparison to those of the conventional enzyme-linked immunosorbent assay (ELISA), the detection time of the developed technique was shortened to 45 minutes and its limit of detection (0.23 pg mL-1) was reduced by 4-5 orders of magnitude. This technique was successfully utilized for detecting PSEP in human urine samples with a recovery rate of 96-116%. Owing to its rapid, ultrasensitive, specific and portable features, the as-designed platform based on GOx@ZIF-8@Ab2 and the PGM device holds great promise as a home-use POCT platform for self-monitoring of CP and other chronic diseases.