Colorimetric detection of electrolyte ions in blood based on biphasic microdroplet extraction.

Timely diagnosis and prevention of diseases require rapid and sensitive detection of biomarkers from blood samples without external interference. Abnormal electrolyte ion levels in the blood are closely linked to various physiological disorders, including hypertension. Therefore, accurate, interference-free, and precise measurement of electrolyte ion concentrations in the blood is particularly important. In this work, a colorimetric sensor based on a biphasic microdroplet extraction is proposed for the detection of electrolyte ions in the blood. This sensor employs mini-pillar arrays to facilitate contact between adjacent blood microdroplets and organic microdroplets serving as sensing phases, with any color changes being monitored through a smartphone's colorimetric software. The sensor is highly resistant to interference and does not require pre-treatment of the blood samples. Remarkably, the sensor exhibits exceptional reliability and stability, allowing for rapid enrichment and detection of K+, Na+, and Cl− in the blood within 10 s (Cl−), 15 s (K+) and 40 s (Na+) respectively. The colorimetric sensor based on biphasic microdroplet extraction offers portability due to its compact size and ease of operation without the need for large instruments. Additionally, it is location-independent, making it a promising tool for real-time biomarker detection in body fluids such as blood. A colorimetric detection of multiple electrolyte ions in blood based on biphasic microdroplet extraction. [Display omitted] • Biphasic microdroplet extraction-based colorimetric sensor was developed for detecting three electrolyte ions in blood. • The sensor exhibited outstanding selectivity and stability for rapid detection of K+, Na+, and Cl−. • The sensor is easy to carry and operate, eliminating the need for sample pre-treatment and large instruments. [ABSTRACT FROM AUTHOR]