A new strategy for simultaneous and portable detection of multiple enzyme activities is highly anticipated for clinical diagnosis and home care. However, the methods developed so far generally suffer from high costs, cumbersome procedures, and heavy reliance on large instruments.

In order to meet the practical requirements of rapid, accurate, and on-site detection of various enzyme activities, Yu Cuiyun/Wei Hua/He Suisui from Nanhua University reported a smartphone assisted programmable microfluidic paper-based analysis device (μ PAD), which uses colorimetric and photothermal signals to simultaneously, accurately, and visually quantify alkaline phosphatase (ALP) and butyrylcholinesterase (BChE). These two-step enzyme nanoenzyme cascade reactions strongly support the direct and excellent processability of the platform, with lower detection limits for ALP and BChE, and an order of magnitude lower detection limit for BChE than other reported paper-based detection methods. Through the analysis of clinical serum samples, the practicality and effectiveness of the platform have been further demonstrated.

Research points

Key point 1: The author developed a smartphone assisted programmable μ PAD sensing platform that utilizes colorimetric and photothermal signals for simultaneous, accurate, and on-site visual detection of ALP and BChE.

Key point 2: The operation of the μ PAD sensing platform is based on two sequential steps. Cobalt doped mesoporous cerium oxide (Co-m-CeO2) exhibits significant peroxidase like activity under neutral conditions. Firstly, it catalyzes the decomposition of H2O2, effectively converting colorless 3,3 ', 5,5' - tetramethylbenzidine (TMB) into blue oxidized TMB (oxTMB). Subsequently, ALP or BChE are added to their respective substrates to produce reducing substances that can to some extent inhibit the conversion of oxTMB, resulting in impaired colorimetric and photothermal signals of oxTMB.

Key point 3: These two-step enzyme nanoenzyme cascade reactions strongly support the direct and excellent processability of the platform, with lower detection limits for ALP and BChE, and an order of magnitude lower detection limit for BChE than other reported paper-based detection methods. Through the analysis of clinical serum samples, the practicality and effectiveness of the platform have been further demonstrated. This innovative platform demonstrates enormous potential as a simple and robust method for simultaneous, accurate, and on-site visual detection of multiple enzyme activities in real samples.

Source: Sensor Expert Network