Nanostructured Optical Photonic Crystal Biosensor for HIV Viral Load Measurement

Abstract

Detecting and quantifying biomarkers and viruses in biological samples have broad applications in early disease diagnosis and treatment monitoring. We have demonstrated a label-free optical sensing mechanism using nanostructured photonic crystals (PC) to capture and quantify intact viruses (HIV-1) from biologically relevant samples. The nanostructured surface of the PC biosensor resonantly reflects a narrow wavelength band during illumination with a broadband light source. Surface-adsorbed biotarget induces a shift in the resonant Peak Wavelength Value (PWV) that is detectable with <10 pm wavelength resolution, enabling detection of both biomolecular layers and small number of viruses that sparsely populate the transducer surface. We have successfully captured and detected HIV-1 in serum and phosphate buffered saline (PBS) samples with viral loads ranging from 104 to 108 copies/mL. The surface density of immobilized biomolecular layers used in the sensor functionalization process, including 3-mercaptopropyltrimethoxysilane (3-MPS), N-gamma-Maleimidobutyryl-oxysuccinimide ester (GMBS), NeutrAvidin, anti-gp120, and bovine serum albumin (BSA) were also quantified by the PC biosensor.

Alcohol sensing over O+E+S+C+L+U transmission band based on porous cored octagonal photonic crystal fiber

“…In medical science, it is becoming more and more popular for bio-photonics [21] and neurophotonics [22]. It is also used in the fields of cancer cell detection, HIV viral load detection [23], protein detection [24], diabetics detection [25], etc. Different types of PCF are used for numerous applications for their superb guiding capability.…”

High aspect ratio titanium nitride trench structures as plasmonic biosensor

“…Reported sensitivities over 1000 nm/RIU were achieved for telecommunication wavelengths around λ = 1500 nm [14] with a larger grating period as the BRIS of RWAs-based sensors scales with their pitch [13]. Moreover, the sensitivity our structure is also comparable and even slightly outperforming those of all-dielectric structures in the near-infrared wavelengths, such as dielectric photonic crystal biosensing platform with 310 nm/RIU for HIV virus detection [44,45], Si resonators with 227 nm/RIU for cancer biomarker detection of prostate specific antigen (PSA, limit of detection, LOD: 0.87 ng/ml) [51], high-contrast grating resonator with 418 nm/RIU for label-free detection of cardiac disease biomaker, serum cardiac troponin I (LOD: 0.1 ng/ml) [46].…”

“…We aim to characterize the sensitivity toward variations in the refractive index of the ambient medium. Typically periodic grating structures made of plasmonic components with a negative permittivity are used for biosensing [44][45][46] detecting the shift of the reflection peak in wavelengths (wavelength interrogation scheme) or change in the reflection angle (angular interrogation). Fig.…”

Point-of-Care Testing in the Time of P5 Medicine: A Preface

“…Direct ways of measuring the amount of the HIV virus present (viral load) allows monitoring of how advanced the infection is and how well treatment is working. (11) The timely initiation of POC-facilitated antiretroviral therapy, especially in the case of pregnant women, greatly helps reduce the risk of further transmission and markedly improves survival by ensuring successful viral suppression. (12) Or consider the case of psychiatric disorders following the experience of a traumatic injury.…”