Journal Article

Covalent and Site-Specific Immobilization of a Fluorogenic Sensor Protein on Cellulose-Based Paper for Detection of Lactate in Cell Culture Media

Bork, Ingo, Höfling, Viktoria, Meckel, Tobias, Biesalski, Markus, Becker, Janine, Kolmar, Harald

2025

Overview

Lactate is a key metabolite with applications ranging from monitoring training efficiency to early sepsis detection and monitoring the metabolic state of cell cultures. In this study, a paper-based lactate sensor utilizing a fluorescent readout was developed. Unlike common lactate dehydrogenase (LDH)-based methods, these sensors use a green fluorescent protein (GFP) or mApple-coupled lactate binding domain, which provides a fluorescent readout upon lactate binding. We demonstrate that immobilizing these proteins on paper does not affect their ability to bind lactate and produce a fluorescent readout, by monitoring lactate levels in the cell culture supernatant applying different cell culture conditions.

• Publisher: MDPI AG
• Subject: Binding / Biosensing Techniques - methods / Biosensors / Cell culture / Cellulose / Cellulose - chemistry / Chemical properties / covalent paper modification / Culture media / Culture media (Biology) / Culture Media - chemistry / Enzymes / Fluorescence / Fluorescent Dyes - chemistry / fluorogenic sensor / Green fluorescent protein / Green Fluorescent Proteins - chemistry / Humans / Immobilization / L-Lactate dehydrogenase / Lactate dehydrogenase / lactate sensor / Lactates / Lactic acid / Lactic Acid - analysis / Measurement / Metabolites / Methods / Monitoring / paper-based sensor / Peptides / Performance evaluation / Proteins / Sensors / Sepsis / site-specific immobilization