pH and Urea Estimation in Urine Samples using Single Fluorophore and Ratiometric Fluorescent Biosensors

Abstract

Kidney diseases remain often undiagnosed due to inefficient screening methods available at patient’s disposal. Early diagnosis and effective management of kidney problems can best be addressed by the development of biosensors for commonly occurring clinical biomarkers. Here we report the development of single fluorophore and dual fluorophore ratiometric biosensors based on alginate microspheres for pH and urea analysis in urine samples. A facile method of air driven atomization was used for developing these polymeric fluorophore and enzyme based biosensors. Ratiometric biosensors were developed using layer-by-layer coating of polyelectrolyte conjugated to reference fluorophores. Biosensing studies using these biosensors showed that samples in pathophysiological range can be measured having pH range of 4–8 and urea levels between 0–50 mM. Testing of urine samples using these biosensors showed that both pH and urea detection can be accurately performed without interference. Thus, we believe that FITC-Dextran and FITC-Dextran/RuBpy based pH and urea biosensors show a great potential to be translated as a point of care device for pH and urea biosensing in early detection and continuous monitoring of kidney diseases.

Fluorescent Biocompatible Platinum-Porphyrin–Doped Polymeric Hybrid Particles for Oxygen and Glucose Biosensing

“…This proves that encapsulation of Pt-Porphyrin in a polymeric matrix will reduce the exposure to cells so that the biocompatibility is improved. Such hybrid microspheres have also been investigated previously for biocompatibility and biosensor performance and results obtained by these reports are also in line with these results 14 , 19 , 21 , 25 .…”

“…1:1, 1:2, 1:3, 1:4 were evaluated for oxygen biosensing ability in a protocol similar to Prasad et al . 14 , 18 , 19 . Fluorescence spectroscopy (with a 150 W Xenon lamp) was used with excitation wavelength of 530 nm and emission wavelength of 645 nm while controlling O 2 bubbling in the samples to determine the oxygen sensitivity.…”

Flexible potentiometric pH sensors for wearable systems

“…89 In fact, pH is a routine clinical investigation performed to assess kidney functionality. 90 In comparison to blood, sweat and urine, saliva is a more readily available body uid, especially for patients suffering from sweat inhibiting conditions or those who suffer from chronic renal failure. 56,91 The real-time chemical analysis of saliva could offer an excellent non-invasive method for monitoring the emotional, hormonal, nutritional, and metabolic state of the body.…”

Swellable Gelatin Methacryloyl Microneedles for Extraction of Interstitial Skin Fluid toward Minimally Invasive Monitoring of Urea

“…[ 52 ] On the other hand, iontophoresis and microdialysis have been explored as alternatives for the minimally invasive monitoring of urea; however, they lack practicality when compared with MNs. [ 40,53,54 ] This indicates that c‐GelMA MNs are a potentially powerful platform for urea diagnosis and can be further explored for the concomitant extraction of multiple metabolites, which will enable the follow‐up of different health conditions and the major noncommunicable diseases.…”