Abstract: Nuclear matrix protein 22 (NMP22) is a FDA approved
biomarker for bladder cancer. The objective of this study is to develop
a simple NMP22 immumosensor (NMP22-IMS) for accurate
measurement of NMP22. The NMP22-IMS was constructed with
NMP22 antibody immobilized on screen-printed carbon electrodes.
The construction procedures and antibody immobilization are simple.
Results showed that the NMP22-IMS has an excellent (r2³0.95)
response range (20 – 100 ng/mL). In conclusion, a simple and reliable
NMP22-IMS was developed, capable of precisely determining urine
NMP22 level.
Abstract: The biomarker for colorectal cancer (CRC) is CEACAM-6 antigen (C6AG). Therefore, this study aims to develop a novel, simple and low-cost CEACAM-6 antigen immumosensor (C6AG-IMS), based on electrical impedance measurement, for precise determination of C6AG. A low-cost screen-printed graphite electrode was constructed and used as the sensor, with CEACAM-6 antibody (C6AB) immobilized on it. The procedures of sensor fabrication and antibody immobilization are simple and low-cost. Measurement of the electrical impedance at a definite frequency ranges (0.43 – 1.26 MHz) showed that the C6AG-IMS has an excellent linear (r2>0.9) response range (8.125 – 65 pg/mL), covering the normal physiological and pathological ranges of blood C6AG levels. Also, the C6AG-IMS has excellent reliability and validity, with the intraclass correlation coefficient being 0.97. In conclusion, a novel, simple, low-cost and reliable C6AG-IMS was designed and developed, being able to accurately determine blood C6AG levels in the range of pathological and normal physiological regions. The C6AG-IMS can provide a point-of-care and immediate screening results to the user at home.
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.