Albumin testing in urine using a smart-phone

Abstract

We demonstrate a digital sensing platform, termed Albumin Tester, running on a smart-phone that images and automatically analyses fluorescent assays confined within disposable test tubes for sensitive and specific detection of albumin in urine. This light-weight and compact Albumin Tester attachment, weighing approximately 148 grams, is mechanically installed on the existing camera unit of a smart-phone, where test and control tubes are inserted from the side and are excited by a battery powered laser diode. This excitation beam, after probing the sample of interest located within the test tube, interacts with the control tube, and the resulting fluorescent emission is collected perpendicular to the direction of the excitation, where the cellphone camera captures the images of the fluorescent tubes through the use of an external plastic lens that is inserted between the sample and the camera lens. The acquired fluorescent images of the sample and control tubes are digitally processed within one second through an Android application running on the same cellphone for quantification of albumin concentration in urine specimen of interest. Using a simple sample preparation approach which takes ~ 5 minutes per test (including the incubation time), we experimentally confirmed the detection limit of our sensing platform as 5–10 μg/mL (which is more than 3 times lower than clinically accepted normal range) in buffer as well as urine samples. This automated albumin testing tool running on a smart-phone could be useful for early diagnosis of kidney disease or for monitoring of chronic patients, especially those suffering from diabetes, hypertension, and/or cardiovascular diseases.

Cellphone-based diagnostic devices

“…As mentioned above, cellphones-based devices can sense biomarkers, provide counting capabilities, and imaging of cells / microorganisms for environmental monitoring and food safety, but may also be used for a variety of clinical applications [79,81,94,104]. The compatibility of cellphone platforms and various RDT formats clearly demonstrates successful quantitative and real-time analysis of immunochromatographic RDTs [89].…”

Towards autonomous lab-on-a-chip devices for cell phone biosensing

“…In contrast with blood, urine samples imply larger volumes, and collection using a cup is a natural alternative. In the case of reusable accessories for cell phones, an albumin urine test has been demonstrated (Coskun et al, 2013). This solution uses 150 µL disposable syringes to inject 25 µL urine into a PDMS detection cell containing the reagents for fluorescence detection using the phone camera interfaced with a reusable instrument (Figure 2d).…”

Mobile Phones Create new Opportunities for Microbiology Research and Clinical Applications

“…In fact, mobile phone-based imaging and sensing platforms have already been used in a variety of applications, including clinical chemistry, biomedical and environmental monitoring [3][4][5], food analysis [6][7][8], detection of different types of chemical and biological analytes such as cells, parasites [9], bacteria [10], eggs [11], proteins [12], various biomarkers [6,7], nanoparticles [13] and even nucleic acids [14][15][16]. In many of these platforms, processing of the acquired data and the resulting computational analysis are done either on the smartphone or over a local or remote server using a customdeveloped smartphone application.…”

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KEYWORDSTogether with their cost-effectiveness, wide-spread use, computational power and connectivity, mobile phones have the potential to transform traditional uses of imaging, sensing and diagnostic systems, especially for point-of-care applications and field settings.In fact, mobile phone-based imaging and sensing platforms have already been used in a variety of applications, including clinical chemistry, biomedical and environmental monitoring [3][4][5], food analysis [6][7][8] [12], various biomarkers [6,7], nanoparticles [13] and even nucleic acids [14][15][16]. In many of these platforms, processing of the acquired data and the resulting computational analysis are done either on the smartphone or over a local or remote server using a customdeveloped smartphone application.

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