Simultaneous Detection of L‐Lactate and D‐Glucose Using DNA Aptamers in Human Blood Serum**

Abstract

L‐lactate is a key metabolite indicative of physiological states, glycolysis pathways, and various diseases such as sepsis, heart attack, lactate acidosis, and cancer. Detection of lactate has been relying on a few enzymes that need additional oxidants. In this work, DNA aptamers for L‐lactate were obtained using a library‐immobilization selection method and the highest affinity aptamer reached a Kd of 0.43 mM as determined using isothermal titration calorimetry. The aptamers showed up to 50‐fold selectivity for L‐lactate over D‐lactate and had little responses to other closely related analogs such as pyruvate or 3‐hydroxybutyrate. A fluorescent biosensor based on the strand displacement method showed a limit of detection of 0.55 mM L‐lactate, and the sensor worked in 90 % serum. Simultaneous detection of L‐lactate and D‐glucose in the same solution was achieved. This work has broadened the scope of aptamers to simple metabolites and provided a useful probe for continuous and multiplexed monitoring.

DNA Sensor-Based Strategy to Visualize the TRPM7 mRNA-Mg2+ Signaling Pathway in Cancer Cells

“…Then, the accuracy of the sensors was evaluated. As shown in Figures A and S6A, sensor 1 has a strong dose-dependent fluorescence response in the target range of 0–2 μM with a detection limit of 1.08 nM (based on the 3σ rule). In addition, sensor 2 has a good detection capability in the concentration range of 0–50 mM for Mg 2+ (Figure D) with a detection limit of 0.08 mM (Figure S6B).…”