Smartphone-based cytometric biosensors for point-of-care cellular diagnostics

Abstract

Analysis on a single-cell basis is both fundamental and meaningful in biomedical research and clinical practice. Flow cytometry is one of the most popular approaches in this field with broad applications in cell sorting, counting, and identification of rare cells. However, the complicated design and bulky size of conventional flow cytometry have restricted their applications mainly in centralized laboratories. With the recent development of smartphone devices, smartphone-based cytometry has been explored and tested for single-cell analysis. Compared with traditional cytometers, smartphone-based cytometric biosensors are more suitable for point-of-care (POC) uses, such as on-site disease diagnosis and personal health monitoring. In this review article, the history of traditional flow cytometry is introduced, and advances of smartphone-enabled cytometry are summarized in detail based on different working principles. Representative POC applications of smartphone cytometers are also discussed. The achievements demonstrated so far illustrate the potential of smartphone-based cytometric devices to transform single-cell measurement in general, with a significant impact in POC diagnostics, preventive medicine, and cell biology.

Label-Free and Simultaneous Mechanical and Electrical Characterization of Single Plant Cells Using Microfluidic Impedance Flow Cytometry

“…Multiparameter measurement including cell concentration, cell size, cell membrane morphology, and cytoplasm compositions have been achieved on such impedance flow cytometry in a label-free and camera-free manner. − In this work, we first compared wall-less protoplast cells derived from different plant species for their respective cell mechanics and then investigated the contribution of PCW to cell mechanical properties. By embedding microelectrodes into constriction microchannel, the real-time electrical impedance of single cells was simultaneously recorded as another biophysical index.…”

Microparticle-tagged image-based cell counting (ImmunoSpin) for CD4 + T cells

“…Visual confirmation and long-term storage are also not possible. Most smartphone cytometry platforms are still limited by the throughput [ 30 ]. We have summarized the specific features of ImmunoSpin compared with several portable cytometries in supplementary Table S3 .…”

A smartphone-read ultrasensitive and quantitative saliva test for COVID-19

“…However, this assay still requires a benchtop fluorescence reader for assay evaluation and quantification, limiting its use to sites equipped with such devices. Smartphone-based devices have become an appealing handheld platform to read multiple different assay types (30)(31)(32)(33)(34), and we hypothesized that a smartphone device could similarly allow sensitive and quantitative readout of saliva CRISPR-FDS assays at sites lacking basic laboratory equipment or infrastructure.…”