# Using Temporally and Spatially Resolved Measurements to Improve the Sensitivity of Fluorescence-Based Immunoassays

## TL;DR

This paper introduces a new algorithm that improves the sensitivity of fluorescence-based immunoassays by combining time and spatial measurements.

## Contribution

A novel signal-processing algorithm that enhances detection and estimation of low-concentration biomarkers using temporally and spatially resolved measurements.

## Key findings

- The new algorithm provides a 2–4-fold improvement in the limit of detection.
- It achieves a ~25% gain in quantitative resolution for human interleukin-8 detection.

## Abstract

Detecting low concentrations of biomarkers is essential in clinical laboratories. To improve analytical sensitivity, especially in identifying fluorescently labeled molecules, typical optical detection systems, consisting of a photodetector or camera, utilize time-resolved measurements. Taking a different approach, magnetic modulation biosensing (MMB) is a novel technology that combines fluorescently labeled probes and magnetic particles to create a sandwich assay with the target molecules. By concentrating the target molecules and then using time-resolved measurements, MMB provides the rapid and highly sensitive detection of various biomarkers. Here, we propose a novel signal-processing algorithm that enhances the detection and estimation of target molecules at low concentrations. By incorporating both temporally and spatially resolved measurements using human interleukin-8 as a target molecule, we show that the new algorithm provides a 2–4-fold improvement in the limit of detection and an ~25% gain in quantitative resolution.