Molecularly imprinted metal-organic frameworks assisted cloth and paper hybrid microfluidic devices for visual detection of gonyautoxin

Marine algal toxin contamination is a major threat to human health. Thus, it is crucial to develop rapid and on-site techniques for detecting algal toxins. In this work, we developed colorimetric cloth and paper hybrid microfluidic devices (μCPADs) for rapid detection of gonyautoxin (GTX1/4) combined with molecularly imprinted polymers. In addition, the metal-organic frameworks (MOFs) composites were applied for this approach by their unique features. Guanosine serves as a dummy template for surface imprinting and has certain structural advantages in recognizing gonyautoxin. MOF@MIPs composites were able to perform a catalytic color reaction using hydrogen peroxide-tetramethylbenzidine for the detection of GTX1/4. The cloth-based sensing substrates were assembled on origami μPADs to form user-friendly, miniaturized colorimetric μCPADs. Combined with a smartphone, the proposed colorimetric μCPADs successfully achieved a low limit of detection of 0.65μg/L within the range of 1-200μg/L for rapid visual detection of GTX1/4. Moreover, the GTX1/4 of real shellfish and seawater samples were satisfactorily detected to indicate the application prospect of the μCPADs. The proposed method shows good potential in the low-cost, stable establishment of assays for the rapid detection of environmental biotoxins. Environmental implication Harmful algal blooms have substantial implications for marine ecosystems and human health. Hence, developing methods for rapid and on-site detection of algal toxins is crucial. We propose a colorimetric strategy based on the molecularly imprinted metal-organic frameworks on cloth and paper hybrid microfluidic devices (μCPADs) for rapid visual detection of gonyautoxin1/4 (GTX1/4) in actual shellfish and seawater. Combined with a smartphone, the proposed μCPADs achieved a low detection limit of 0.65μg/L within the range of 1-200μg/L. The method shows good potential in the low-cost, stable establishment of assays for rapid detection of environmental biotoxins.