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Updated: May 7, 2025
Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor
Published on: February 16, 2018
An antibody-free bio-layer interferometry biosensor for immunoglobulin G1 detection in human serum by using
S Ventisette1, T Ferruzzi1, D Sestaioni1
1Department of Chemistry "Ugo Schiff', University of Florence, Via della Lastruccia, 3-13, 50019, Sesto Fiorentino, Italy.
Insights
This study introduces a novel biosensor using molecularly imprinted polynorepinephrine (MIPNE) with Bio-Layer Interferometry (BLI) for detecting IgG1. The assay demonstrates high selectivity and accuracy in whole human serum, paving the way for advanced diagnostics.
Area of Science:
- Biomolecular interaction analysis
- Biosensor technology
- Analytical chemistry
Background:
- Bio-Layer Interferometry (BLI) is a label-free technique for studying biomolecular interactions.
- Current BLI assays often rely on traditional biological receptors.
- There is a need for robust and selective detection methods, especially in complex biological samples like serum.
Purpose of the Study:
- To develop and validate the first Bio-Layer Interferometry (BLI) bioassay utilizing a molecularly imprinted polynorepinephrine (MIPNE) mimetic receptor.
- To detect and quantify immunoglobulin G isotype 1 (IgG1) in whole human serum.
- To evaluate the analytical performance and selectivity of the MIPNE-BLI assay against other immunoglobulin classes and isotypes.
Main Methods:
- Development of a BLI sensor with immobilized MIPNE receptors on optical fibers.
- Optimization of chemical linkers for receptor immobilization.
- Testing the bioassay in buffer and whole human serum to determine limit of detection (LOD), limit of quantification (LOQ), and precision (RSD, RE).
- Assessment of selectivity against other IgG isotypes and immunoglobulin classes.
Main Results:
- The MIPNE-BLI assay successfully detected IgG1 in both buffer and whole human serum.
- Excellent analytical parameters were achieved: LOD = 0.54 ± 0.01 μg mL⁻¹, LOQ = 2.09 ± 0.02 μg mL⁻¹, with low average relative standard deviation (avRSD) of 5.3% in buffer and 3% in serum.
- The assay demonstrated high selectivity for IgG1 over other IgG isotypes and Ig classes.
- Minimal matrix effects were observed in whole serum (%RE = 0.3%).
Conclusions:
- The study successfully demonstrates the integration of polynorepinephrine (PNE)-based molecular imprinting with BLI platforms.
- The developed MIPNE-BLI bioassay offers a sensitive, selective, and robust method for IgG1 detection in complex matrices like human serum.
- This technology holds significant potential for diverse analytical and diagnostic applications in healthcare and beyond.
Abstract:
Bio-Layer Interferometry (BLI) has emerged as a versatile technique in affinity-based biosensing, analogous to Surface Plasmon Resonance. BLI enables real-time, label-free detection, and quantification of biomolecular interactions between an immobilized receptor and an analyte in solution. The BLI sensor comprises an optical fiber with an internal reference layer at the end and an external biocompatible layer where biological receptors are immobilized and exposed to the solution. We report the first BLI bioassay using a mimetic receptor based on molecularly imprinted polynorepinephrine (MIPNE) for detecting immunoglobulin G isotype 1 in whole, untreated, human serum. Using BLI fiber optics with different chemical linkers, we compared the analytical performance, with a focus on selectivity against other Ig classes and across the four IgG isotypes. The bioassay displayed the ability to detect IgG1 with excellent analytical parameters both in buffer condition (LOD = 0.54 ± 0.01 μg mL-1, LOQ = 2.09 ± 0.02 μg mL-1, avRSD = 5.3%) and in whole serum (%RE = 0.3%, avRSD = 3%). These findings highlight the potential of integrating PNE-based molecular imprinting technology with BLI platforms for diverse analytical and diagnostic applications.
