Scientists at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) have developed a smartphone-enabled fluorescence platform for detecting amyloid-β (Aβ), a key biomarker associated with Alzheimer’s disease (AD), potentially offering a more accessible approach to biomarker screening.

The technology combines a novel fluorescent probe, TZ-48, with a smartphone-integrated system called ADxFluor. When TZ-48 interacts with Aβ, it undergoes changes in fluorescence intensity and lifetime. 

These changes can be captured and quantified using a dedicated smartphone application, enabling rapid measurement of Aβ.

Alzheimer’s disease is a progressive neurodegenerative disorder associated with memory loss, cognitive decline and behavioural changes. 

The aggregation of Aβ into fibrils and extracellular plaques is a central feature of AD pathology and represents an early disease-associated biomarker.

Currently used imaging approaches such as PET and MRI can provide important diagnostic information but require expensive infrastructure and specialised expertise. Blood- and cerebrospinal-fluid-based assays for Aβ and tau offer less invasive alternatives but can also be costly and technically complex. 

The researchers said these limitations highlight the need for diagnostic technologies that are sensitive, scalable and easier to deploy.

The JNCASR team designed TZ-48 as a fluorescence lifetime-responsive probe capable of selectively detecting Aβ fibrils through increased fluorescence and distinct fluorescence lifetime signatures. Fluorescence lifetime-based detection can offer greater robustness because the measurement is relatively less dependent on probe concentration and photobleaching compared with conventional fluorescence intensity measurements.

Published in ACS Chemical Neuroscience, the research showed that TZ-48 has blood-brain barrier permeability and can label Aβ plaques in transgenic Alzheimer's disease mouse brains. The probe was also compatible with confocal laser scanning microscopy and fluorescence lifetime imaging microscopy (FLIM), enabling quantitative mapping of Aβ burden across different disease stages.

Beyond brain tissue imaging, the researchers demonstrated that TZ-48 could detect Aβ in cerebrospinal fluid and blood serum and distinguish Alzheimer's disease model mice from healthy animals.

To move the technology towards a more portable diagnostic format, researchers Krithi K. Bhagavath, Madhu Ramesh, Yogendra Kumar, Sabyasachi Mandal, Hiriyakkanavar Ila and Thimmaiah Govindaraju developed the ADxFluor smartphone-integrated platform. The system uses the fluorescence response generated by TZ-48 to quantify serum Aβ levels through smartphone-based analysis.

The researchers said the platform integrates brain imaging, biofluid biomarker detection and smartphone-based quantification, potentially providing a foundation for portable diagnostic technologies for Alzheimer's disease and other neurodegenerative disorders.

While the findings represent a promising technological advance, the work remains at the research and preclinical stage. Further validation in human clinical studies would be required to establish its diagnostic performance and determine whether the technology can be translated into routine point-of-care Alzheimer's disease screening.