University:
Boston University
Course:
SAR HP 151 | Introduction to Health Professions
Academic year:

2024
Views:

91

Pages:

14
Author:

vielay3og

Point of Care Biosensors Spectral Reflectance Imaging Biosensors (SRIB) Spectral Reflectance Imaging Biosensors (SRIB) • Point-of-care medicine and public health • 325 million DALYs per year (disability-adjusted life years) from the six highest infectious diseases • More appropriate diagnostic tools for global health applications, especially point-of-care, developing world – ELISA (Enzyme-linked Immunosorbent Assay) – labeled, lab, skill – SPR (surface plasmon resonance) label free, temperature sensitive, laboratory – Microarray – label efficiency, quenching, bleaching, probe affinity Spectral Reflectance Imaging Biosensors (SRIB) SRIB Principles Spectral Reflectance Imaging Biosensors (SRIB) 1000-spot array December 2009 Pathogen Detection Approaches Antigen Detection Antigen A Antigen C Antigen D Analyte Flow Diagnosis + ΔZ= 0.1nm Antibody A B C D E A B C D E - Bioterror Agent: Receptor Array Slide A B C Whole virus detection NanoA resonator A A l D E Spectral Reflectance Imaging Biosensors (SRIB) Single Particle Detection Fluorescent 100nm Carboxyl modified beads immobilized on Lysine surface. Incubation time 15min, 10^8 particles/ml Surface Protocols • Polymer Coating • Epoxysilanization (Control) ▫ 0.1M NaOH ▫ 4hr γ-GPS(glycidil propyl silane) (5% in dry toluene) at 37 C ▫ toluene/methanol wash ▫ overnight at 100 C oxide – – – – 0.1M NaOH 30min polymer extensive wash Vacuum dry at 80 C oxide silicon silicon Spotting of Oligonucleotides ▫5′-amine-modified and 3’-Cy5-modified oligos in sodium phosphate buffer, noncontact microarray spotter. oxide silicon Spotting oxide silicon Functional antibodies on the surface 8 G. Pirri et al., Anal. Chem. 76, 1352-1358 (2004) A. Yalcin et al., Anal. Chem. 81, 625-630 (2009) Incremental surface accumulation (ng/mm2) 7 6 5 4 3 2 1 0 -1 20 40 60 80 100 time (min.) mouse IgG anti-mouse IgG rabbit IgG anti-rabbit IgG 120 140 160 180 Interferometry with LEDs vs. Laser LED Emission • Oxide thickness affects curve periodicity 1 • Full period of curve must 0.8 be sampled 0.6 • Laser has narrow (~20nm) tuning range 0.4 • To use laser, thick oxide is 0.2 needed Reflectivity 0.9 0.8 Reflectivity Reflectivity 0.7 0.6 0.5 0.4 0.3 0.2 720 760 780 800 Wavelength (nm) SiO2 Si 17μm 0.1 400 450 500 550 Wavlength(nm) 600 650 0 400 450 500 550 Wavelength(nm) 600 650 SiO2 Si 700 700 500nm High Throughput Biosensors Using Plasmonic Nanostructures Nano-Photonics: Manipulating Light On-Chip Photonic Crystals Applications: I- Life-Science  Proteomics Cancer, Alzheimer’s Plasmonic Nanoholes II- Bio-defense Infectious Diseases Viral Out-breaks III-Pharmacology  Drug/Vaccine Discovery Photonic nano-resonators can enable:  Localize light below sub-diffraction limit & enhance the field  Increase light-molecule interaction Compact & Portable On-chip platform: Integration NanoAntennas Mass Transport Limitation Problem Nano scaled surface biosensors offers 1)Femto-molar sensitivity label-free detection 2)On-chip integration with microfluidics for point of care applications Depletion zone BUT… Conventional fluidic channels leads 1) Passive delivery 2) Formation of depletion zones 3) Mass transport limitation inlet outlet sensor substrate Direct Targeting Flow Scheme Proposed flow scheme - Transport solutions at nano-scales - Overcome mass transport limitations - Actively control the fluidic flow - Apply to highly viscosity solutions Glass Sensor PDMS Inlet Outlet Glass This scheme can be employed at any nano-hole openings based sensors 300 nm 400 nm