TY - JOUR
T1 - On-hand tool for ammonium and urea determination in saliva to monitor chronic kidney disease – design of a couple of microfluidic paper-based devices
AU - Ferreira, Francisca T. S. M.
AU - Mesquita, Raquel B. R.
AU - Rangel, António O. S. S.
N1 - Funding Information:
F.T.S.M.F. thanks FCT—Fundação para a Ciência e a Tecnologia for the Grant SFRH/BD/144962/2019. This work was supported by National Funds from FCT through project UIDB/50016/2020.
Funding Information:
F.T.S.M.F. thanks FCT—Fundação para a Ciência e a Tecnologia for the Grant SFRH/BD/144962/2019. This work was supported by National Funds from FCT through project UIDB/50016/2020.
Publisher Copyright:
© 2023 The Author(s)
PY - 2023/10
Y1 - 2023/10
N2 - In this work, two microfluidic paper-based analytical devices (μPADs) were developed for the quantification of urea and NHx in human saliva to aid in the diagnosis/monitoring of chronic kidney disease (CKD). The NHx determination was based on the conversion of ammonium to ammonia, followed by its diffusion through a hydrophobic membrane and then the color change of bromothymol blue (BTB) indicator. In the urea determination, prior to the ammonium conversion and BTB color change, the enzymatic conversion of urea into ammonium was produced, using urease. Several optimization studies were carried out to attain a quantification range of 0.10–5.0 mM with 0.032 mM limit of detection for the NHx μPAD, and a determination range of 0.16–5.0 mM with 0.049 mM limit of detection for the urea μPAD. The method accuracy was assessed, and the measurements obtained with NHx μPAD were compared with the ones obtained from an ammonia ion selective electrode; while the measurements of the urea μPAD were compared with the ones obtained from a commercially available kit. There were no statistically significant differences between methods, proving that both NHx and urea μPAD were effective on-hand tools for CKD monitoring in saliva. To evaluate their functionality as point-of-care devices, stability studies were also performed and revealed that both NHx and urea μPAD were stable when stored in a vacuum for 2 and 1 month, respectively. After the sample introduction, the NHx μPAD could be scanned within the first 2 h and the urea μPAD within 1 h.
AB - In this work, two microfluidic paper-based analytical devices (μPADs) were developed for the quantification of urea and NHx in human saliva to aid in the diagnosis/monitoring of chronic kidney disease (CKD). The NHx determination was based on the conversion of ammonium to ammonia, followed by its diffusion through a hydrophobic membrane and then the color change of bromothymol blue (BTB) indicator. In the urea determination, prior to the ammonium conversion and BTB color change, the enzymatic conversion of urea into ammonium was produced, using urease. Several optimization studies were carried out to attain a quantification range of 0.10–5.0 mM with 0.032 mM limit of detection for the NHx μPAD, and a determination range of 0.16–5.0 mM with 0.049 mM limit of detection for the urea μPAD. The method accuracy was assessed, and the measurements obtained with NHx μPAD were compared with the ones obtained from an ammonia ion selective electrode; while the measurements of the urea μPAD were compared with the ones obtained from a commercially available kit. There were no statistically significant differences between methods, proving that both NHx and urea μPAD were effective on-hand tools for CKD monitoring in saliva. To evaluate their functionality as point-of-care devices, stability studies were also performed and revealed that both NHx and urea μPAD were stable when stored in a vacuum for 2 and 1 month, respectively. After the sample introduction, the NHx μPAD could be scanned within the first 2 h and the urea μPAD within 1 h.
KW - CKD
KW - Saliva sample
KW - Sensors
KW - Urease conversion
KW - μPADs
UR - http://www.scopus.com/inward/record.url?scp=85166011624&partnerID=8YFLogxK
U2 - 10.1016/j.microc.2023.109102
DO - 10.1016/j.microc.2023.109102
M3 - Article
AN - SCOPUS:85166011624
SN - 0026-265X
VL - 193
JO - Microchemical Journal
JF - Microchemical Journal
M1 - 109102
ER -