Measuring kinetic parameters using quantum plasmonic sensing

TL;DR

This paper explores how quantum sensing techniques, specifically using quantum states like Fock and squeezed states, can improve the precision of measuring kinetic parameters in molecular interactions with plasmonic sensors.

Contribution

It introduces a theoretical framework for using quantum states to enhance kinetic parameter measurements in plasmonic sensors, a novel approach in biosensing.

Findings

Quantum states improve measurement precision over classical light.

Both large and small sensor responses benefit from quantum enhancement.

Theoretical results guide design of more precise quantum biosensors.

Abstract

The measurement of parameters that describe kinetic processes is important in the study of molecular interactions. It enables a deeper understanding of the physical mechanisms underlying how different biological entities interact with each other, such as viruses with cells, vaccines with antibodies, or new drugs with specific diseases. In this work, we study theoretically the use of quantum sensing techniques for measuring the kinetic parameters of molecular interactions. The sensor we consider is a plasmonic resonance sensor -- a label-free photonic sensor that is one of the most widely used in research and industry. The first type of interaction we study is the antigen BSA interacting with antibody IgG1, which provides a large sensor response. The second type is the enzyme carbonic anhydrase interacting with the tumor growth inhibitor benzenesulfonamide, which produces a small sensor response. For both types of interaction we consider the use of two-mode Fock states, squeezed vacuum states and squeezed displaced states. We find that these quantum states offer an enhancement in the measurement precision of kinetic parameters when compared to that obtained with classical light. The results may help in the design of more precise quantum-based sensors for studying kinetics in the life sciences.