Development of a High-Accuracy, Low-Cost, and Portable Fluorometer with Smartphone Application for the Detection of Urinary Albumin towards the Early Screening of Chronic Kidney and Renal Diseases.

This study presents the development of a portable fluorometer with a smartphone application designed to facilitate the early screening of chronic kidney and renal diseases by enabling the sensitive detection of urinary albumin. Utilizing a fluorescence-based aptasensor, the device achieved a linear calibration curve (0.001-1.5 mg/mL) with a linearity of up to 0.98022 and a detection limit of 0.203 µg/mL for human serum albumin (HSA). The analysis of 130 urine samples demonstrated comparable performance between this study's fluorometer, a commercial fluorometer, and the standard automated method. These findings validate the feasibility of the portable fluorometer and aptasensor combination as a reliable instrument for the sensitive and specific measurement of HSA in urine samples. Moreover, the fluorometer's portability offers potential applications in portable point-of-care testing, enhancing its utility in clinical settings for early disease screening.

Albuminuria detection using graphene oxide-mediated fluorescence quenching aptasensor.

A simple and sensitive graphene oxide-mediated fluorescence quenching aptasensor is developed to quantify albuminuria in urine samples. The developed aptasensor used the specific target binding property of aptamer and fluorescence quenching property of graphene oxide to determine the concentration of human serum albumin in urine. The limit of detection of the developed platform is 0.05 µg.mL-1 and the detection range is 0.1-600 µg.mL-1, which covers the albuminuria concentration range present in normal human urine and the urine of the patient with chronic kidney disease. This approach can be modified to measure albuminuria using a high-throughput quantification platform and portable point of care testing. In addition, the production cost for one reaction is cheaper than those for the standard automated method. Therefore, this aptasensor has significant potential for commercialization and public use.•Our protocol is customized by using the fluorescence quenching property of graphene oxide and specific binding property of human serum albumin aptamer to detect human serum albumin in urine sample•The limit of detection of our developed platform is 0.05 µg.mL-1•The detection range of our aptasensor is 0.1-600 µg.mL-1.

Sensitive detection of albuminuria by graphene oxide-mediated fluorescence quenching aptasensor.

Albuminuria is a pathological condition wherein the human serum albumin (HSA) protein is present in abnormally excess amounts in the urine. A simple and sensitive graphene oxide-mediated fluorescence quenching aptasensor is developed to quantify albumin in urine samples and HSA in serum samples. The aptamer-bound HSA used in this aptasensor has hairpin structures, which are characteristic of the aptamer binding site. The limit of detection of the developed platform is 0.05 µg·mL-1 and the detection range is 0.1-14.0 µg·mL-1, which covers the albuminuria concentration range present in normal human urine and the urine of the patient with kidney diseases. This approach can be modified to measure HSA using a high-throughput quantification platform and portable point of care testing. In addition, the production cost for one reaction is cheaper than those for other standard automated methods. Therefore, this aptasensor has significant potential for commercialization and wide-scale public use.