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Current diagnostics call for rapid, sensitive, and selective screening of physiologically important biomarkers. Point-of-care (POC) devices for the rapid, reliable, and easy acquisition of bioinformation at, or near the patient, offer opportunities for better healthcare management. Electrochemical biosensors with high sensitivity and ease of miniaturization are advantageous for such applications. We report a photolithographically micropatterned PEDOT:PSS and silk protein-based fully organic 3-electrode sensor (O3ES) for ultralow volume (single drop—10 µL) detection of analytes in whole blood. The O3ES produces reliable electrochemical signals in whole blood from a mouse model with minimal biofouling interference. The O3ES is demonstrated as a portable device for the simultaneous detection of dopamine, ascorbic acid and uric acid using voltammetry techniques. The O3ES displays excellent sensitivity towards each analyte in whole blood, and in the presence of each other. The water-based, ambient processing of the sensors allows the immobilization of enzymes in the organic working electrode. Amperometric detection of uric acid via uricase with high sensitivity in whole blood is demonstrated. Finally, the performance of the O3ES under enzymatic degradation is studied by monitoring sensitivity over an operating lifetime of ~14 days. This work demonstrates the realization of low-cost, disposable POC sensors capable of detecting blood metabolites using ultralow sample volumes. [ABSTRACT FROM AUTHOR]

• Genetic algorithm boosts the synthesis of high-quality MOFs via a microdroplet route. • ZIF-8 with highest surface area (1748 m2/g) is achieved with least trial and error. • General guidance is derived and demonstrated with the synthesis of ZIF-67. As an emerging strategy for the synthesis of metal-organic frameworks (MOFs), a microdroplet-based spray method holds merits of improved heat and mass transfer rates, which allows the formation of MOF crystals in a much faster manner. To optimize the spray route for the MOF synthesis, further exploration is needed to understand the dominant variables controlling the quality of the products. With a series of experiments and advanced computational analysis, we present here general guidance for the synthesis of representative zeolitic imidazolate frameworks (i.e., ZIF-8 and ZIF-67) using the spray route. [ABSTRACT FROM AUTHOR]