A handheld-type total integrated capillary electrophoresis system for SARS-CoV-2 diagnostics: Power, fluorescence detection, and data analysis by smartphone

A micro-capillary electrophoresis (mu CE) system is one of the widely adopted techniques in the molecular diagnostics and DNA sequencing due to the benefits of high resolution, rapid analysis, and low reagent consumption, but due to the requirements of bulky high-power suppliers and an expensive laser-induced fluorescence detector module, the conventional set-up of mu CE system is not adequate for point-of-care (POC) molecular diagnostics. In this study, we constructed a miniaturized and integrated mu CE system which can be manipulated by a smartphone. The smartphone not only powers two boost converters and an excited laser, but also controls the relay for the power switch. Moreover, the complementary metal-oxide-semiconductor (CMOS) camera of the smartphone was used for detecting the fluorescence signal of amplicons amplified with reverse transcription-polymerase chain reaction (RT-PCR). We also developed a web-based application so that the raw data of the recorded fluorescence intensity versus the running time can display typical capillary electropherograms on the smartphone. The total size of the hand-held mu CE system was 9.6 cm [Width] x 22 cm [Length] x 15.5 cm [Height], and the weight was similar to Psi 1 kg, which is suitable for POC DNA testing. In the integrated smartphone-associated mu CE system, we could accurately analyze two genes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), namely N gene and S gene along with two bracket ladders in 6 min to identify SARSCoV-2. Such an advanced mu CE platform can be applied for a variety of on-site molecular diagnostics fields with user-friendliness.

Automated summary

The study successfully developed an integrated micro-capillary electrophoresis system controlled by a smartphone, which is efficient and accurate for on-site molecular diagnostics.