Multiplex assays of bladder cancer protein markers with magnetic structural color hydrogel microcarriers based on microfluidics.

• Microfluidics-based magnetic structure color hydrogel microcarrier is proposed. • The microcarrier had high sensitivity and specificity for multiplex analysis. • The microcarrier can detect sample with extremely low volume (as low as 10 μL). • The magnetic control effect improves the sensitivity and efficiency of detection. • The microcarriers are potential for the diagnosis of bladder cancer. Bladder cancer is one of the most common malignant tumors of the urinary system with a significantly increased incidence in recent years. Tumor biomarkers detection with high specificity and sensitivity bears great significance in clinical diagnosis and treatment. Here, we propose a novel microfluidics-based magnetically responsive structural color hydrogel microcarrier as the multiplex detection platform, with the advantages of easy accessibility and high sensitivity. The resin material with the superior mechanical property was applied to prepare the inverse opal as the framework, in whose gaps perfused with a multifunctional hydrogel composed of polyethylene glycol diacrylate (PEGDA), acrylic acid (AA) and Fe 3 O 4 nanoparticles. The composition enabled the microcarrier with high mechanical strength, low non-specific molecular adhesion, and directional magnetic motion ability, which significantly improved the detection efficiency of the platform. The results demonstrated that our detection system had good sensitivity and reliable specificity in the multiplex analysis of bladder cancer-related protein nuclear matrix protein 22, human bladder tumor antigen and fructose-1,6-diphosphate. Furthermore, the microcarriers were proved to have an ideal application prospect in clinical diagnosis and monitoring. Therefore, magnetically responsive structural color hydrogel microcarriers were suitable for the construction of liquid chips for bladder cancer protein markers. [ABSTRACT FROM AUTHOR]