A 3D-printed integrated maneuverable device for sensitive colorimetry of Pseudomonas aeruginosa

Timely and sensitive monitoring of pathogens in clinical specimen is highly demanded for efficient control and precise treatment of infectious diseases. Herein, a 3D-printed maneuverable device integrating incubation, washing, and detection functions was manufactured for colorimetry of Pseudomonas aeruginosa (P. aeruginosa) using transparent resin. The device combined with magnetic beads (MBs) can achieve specific separation and efficient enrichment of P. aeruginosa. Furthermore, it can be directly fixed onto a 96-well plate holder for colorimetry. Specifically, a P. aeruginosa bacteriophage termed as JZ1 acquired from river water was applied as a recognition reagent to functionalize the separation vectors MBs. Then, a nanoconfinement MOFs material termed as PCN-222(Pt) with remarkable peroxidase-like activity was conjugated with polymyxin B to act as a signal tracer. With the formation of target bacterial complexes, the bound PCN-222(Pt) catalyzed the color reaction of 3,3',5,5'-tetramethylbenzidine to enable quantitative colorimetry of P. aeruginosa by the maneuverable device. With this device, P. aeruginosa can be quantified within 40 min, with a dynamic range of 1.9 × 10² ∼ 1.9 × 10⁶ cfu mL^-1. The results for colorimetry of P. aeruginosa in diverse sample matrixes demonstrated its satisfactory practicability. This work provides a facile, timely, and cost-effective technique for point-of-care testing of pathogens.