Filter Paper Based Fluorescence Sensor For Alkaline Phosphatase Detection Via Reversible Pyrene-Polymer Aggregation

In this work, a selective and affordable supramolecular sensor is described for the detection of alkaline phosphatase (ALP) which act as biomarker for liver, bone disorders and cancers. The sensor contains a dynamic pair of pyrene-based dye (PTS) and polyallylamine (PAA) polymer that produces a change in fluorescence when ALP works. ALP will hydrolyze adenosine triphosphate (ATP). ATP makes PAA bind, disturbs PTS-PAA complex and change the fluorescence of PTS-PAA from 500 nm to 385 nm. ATP hydrolysis acts to break down ATP and restore the aggregates, making the fluorescence reappear. With this kind of response, ALP measurements can be accurate, quick and can reliably detect at levels as low as 63.3 µU/mL and as high as 150 mU/mL in human serum.

The dual-emission approach allows the sensor to self-correct, so possible effects from pH, temperature or light are significantly reduced. Making the sensor is simple because it relies on environmentally friendly materials, Commercial available probes, without needing complex manufacturing. As checked in real serum, the sensor works equally well as ALP concentrations vary. The use of supramolecular sensing on a filter paper stage makes it easier for healthcare staff everywhere to detect enzymes, even in remote or resource-constrained areas.

Using the sensor together with filter paper makes the assay portable and simpler to use, making it perfect for point-of-care testing in poor-resource places. There is very little interference in the system, so it remains accurate when checking ALP in biological samples.