Abstract: Acute kidney injury (AKI) is a new worldwide public
health problem. A diagnosis of this disease using creatinine is still a
problem in clinical practice. Therefore, a measurement of biomarkers
responsible for AKI has received much attention in the past couple
years. Cytokine interleukin-18 (IL-18) was reported as one of the
early biomarkers for AKI. The most commonly used method to
detect this biomarker is an immunoassay. This study used a planar
platform to perform an immunoassay using fluorescence for
detection. In this study, anti-IL-18 antibody was immobilized onto a
microscope slide using a covalent binding method. Make-up samples
were diluted at the concentration between 10 to 1000 pg/ml to create
a calibration curve. The precision of the system was determined
using a coefficient of variability (CV), which was found to be less
than 10%. The performance of this immunoassay system was
compared with the measurement from ELISA.
Abstract: We present a dextran modified silicon microring
resonator sensor for high density antibody immobilization. An array
of sensors consisting of three sensor rings and a reference ring was
fabricated and its surface sensitivity and the limit of detection were
obtained using polyelectrolyte multilayers. The mass sensitivity and
the limit of detection of the fabricated sensor ring are 0.35 nm/ng
mm-2 and 42.8 pg/mm2 in air, respectively. Dextran modified sensor
surface was successfully prepared by covalent grafting of oxidized
dextran on 3-aminopropyltriethoxysilane (APTES) modified silicon
sensor surface. The antibody immobilization on hydrogel dextran
matrix improves 40% compared to traditional antibody
immobilization method via APTES and glutaraldehyde linkage.