Detection of Human Ig G Using Photoluminescent Porous Silicon Interferometer

Abstract

Photoluminescent porous silicon (PSi) interferometers having dual optical properties, both Fabry-Pérot fringe and photolumincence (PL), have been developed and used as biosensors for detection of Human Immunoglobin G (Ig G). PSi samples were prepared by electrochemical etching of p-type silicon under white light exposure. The surface of PSi was characterized using a cold field emission scanning electron microscope. The sensor system studied consisted of a single layer of porous silicon modified with Protein A. The system was probed with various fragments of aqueous human immunoglobin G (Ig G) analyte. Both reflectivity and PL were simultaneously measured under the exposure of human Ig G. An increase of optical thickness and decrease of PL were obtained under the exposure of human Ig G. Detection limit of 500 fM was observed for the human Ig G.

Immobilization of hydroxocobalamin (vitamin B12) on aptes-functionalized mesoporous silicon

“…The surface of freshly prepared PS layers (figure 3(a)) is well known to be covered by hydrogen species peaking around 2100 cm −1 (Si-H x , x=1-3) [14,19]. ATR-FTIR of PS-APTES (figure3(a)) confirms the attachment of hydrolyzed APTES on PS layers with the presence of bands associated to the CH 2 stretching modes at 2925 and 2854 cm −1 while the 1572 and 1475 cm −1 peaks are assigned to NH 2 deformation modes of the amine groups of the APTES [14,20]. In addition, the asymmetric stretching mode of Si-O-Si siloxane groups is peaking at 1004 cm −1 confirming the covalent binding of APTES on the silicon surface [13].…”

Smart Hydrogel Grating Immunosensors for Highly Selective and Sensitive Detection of Human-IgG

“…Typically, detection of immunoglobulin G can be achieved by using electrochemical methods, 9,10 quartz crystal microbalances, 11,12 surface plasmon resonance, 13,14 enzyme-linked immunosorbent assay (ELISA), 15 and chemiluminescent methods. 16 As compared to the conventional detection methods, diffraction grating sensors provide an efficient and versatile approach for biomarker detection because of their advantages such as low cost, easy operation, and high sensitivity and flexibility. 17−22 Usually, the detections with diffraction grating sensors require analyte-induced structural changes of the diffraction gratings to regulate the diffracted optical signals as readouts.…”

“…Detection of biomarkers is crucial for early diagnosis of diseases, assessment of disease severity, and reflection of drug effects and pharmacokinetics. − Especially, human immunoglobulin G (H-IgG) is one of the important biomarkers that can indicate diseases such as primary or secondary immunodeficiency and infection diseases, − which makes the detection of H-IgG highly important in clinical diagnostics. Typically, detection of immunoglobulin G can be achieved by using electrochemical methods, , quartz crystal microbalances, , surface plasmon resonance, , enzyme-linked immunosorbent assay (ELISA), and chemiluminescent methods . As compared to the conventional detection methods, diffraction grating sensors provide an efficient and versatile approach for biomarker detection because of their advantages such as low cost, easy operation, and high sensitivity and flexibility. − Usually, the detections with diffraction grating sensors require analyte-induced structural changes of the diffraction gratings to regulate the diffracted optical signals as readouts.…”