TY - JOUR
T1 - Investigating the influence of temperature on the kaolinite-base synthesis of Zeolite and Urease immobilization for the potential fabrication of electrochemical urea biosensors
AU - Anderson, David Ebo
AU - Balapangu, Srinivasan
AU - Fleischer, Heidimarie N.A.
AU - Viade, Ruth A.
AU - Krampa, Francis D.
AU - Kanyong, Prosper
AU - Awandare, Gordon A.
AU - Tiburu, Elvis K.
N1 - Publisher Copyright:
© 2017 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2017/8/8
Y1 - 2017/8/8
N2 - Temperature-dependent zeolite synthesis has revealed a unique surface morphology, surface area and pore size which influence the immobilization of urease on gold electrode supports for biosensor fabrication. XRD characterization has identified zeolite X (Na) at all crystallization temperatures tested. However, N2 adsorption and desorption results showed a pore size and pore volume of zeolite X (Na) 60 °C, zeolite X (Na) 70 °C and zeolite X (Na) 90 °C which range from 1.92 nm to 2.45 nm and 0.012 cm3/g to 0.061 cm3/g, respectively, with no significant differences. The specific surface area of zeolite X (Na) at 60, 70 and 90 °C was 64 m2/g, 67 m2/g and 113 m2/g, respectively. The pore size, specific surface area and pore volumes of zeolite X (Na) 80 °C and zeolite X (Na) 100 °C were dramatically increased to 4.21 nm, 295 m2/g, 0.762 cm3/g and 4.92 nm, 389 m2/g, 0.837 cm3/g, in that order. The analytical performance of adsorbed urease on zeolite X (Na) surface was also investigated using cyclic voltammetry measurements, and the results showed distinct cathodic and anodic peaks by zeolite X (Na) 80 °C and zeolite X (Na) 100 °C. These zeolites’ molar conductance was measured as a function of urea concentration and gave an average polynomial regression fit of 0.948. The findings in this study suggest that certain physicochemical properties, such as crystallization temperature, are critical parameters for improving the morphological properties of zeolites synthesized from natural sources for various biomedical applications.
AB - Temperature-dependent zeolite synthesis has revealed a unique surface morphology, surface area and pore size which influence the immobilization of urease on gold electrode supports for biosensor fabrication. XRD characterization has identified zeolite X (Na) at all crystallization temperatures tested. However, N2 adsorption and desorption results showed a pore size and pore volume of zeolite X (Na) 60 °C, zeolite X (Na) 70 °C and zeolite X (Na) 90 °C which range from 1.92 nm to 2.45 nm and 0.012 cm3/g to 0.061 cm3/g, respectively, with no significant differences. The specific surface area of zeolite X (Na) at 60, 70 and 90 °C was 64 m2/g, 67 m2/g and 113 m2/g, respectively. The pore size, specific surface area and pore volumes of zeolite X (Na) 80 °C and zeolite X (Na) 100 °C were dramatically increased to 4.21 nm, 295 m2/g, 0.762 cm3/g and 4.92 nm, 389 m2/g, 0.837 cm3/g, in that order. The analytical performance of adsorbed urease on zeolite X (Na) surface was also investigated using cyclic voltammetry measurements, and the results showed distinct cathodic and anodic peaks by zeolite X (Na) 80 °C and zeolite X (Na) 100 °C. These zeolites’ molar conductance was measured as a function of urea concentration and gave an average polynomial regression fit of 0.948. The findings in this study suggest that certain physicochemical properties, such as crystallization temperature, are critical parameters for improving the morphological properties of zeolites synthesized from natural sources for various biomedical applications.
KW - Biosensor
KW - Electrochemical
KW - Nanoparticles
KW - Urea
KW - Zeolites
UR - http://www.scopus.com/inward/record.url?scp=85027016549&partnerID=8YFLogxK
U2 - 10.3390/s17081831
DO - 10.3390/s17081831
M3 - Article
C2 - 28786961
AN - SCOPUS:85027016549
SN - 1424-8220
VL - 17
JO - Sensors (Switzerland)
JF - Sensors (Switzerland)
IS - 8
M1 - 1831
ER -