A Novel Microfluidic Device Integrated with Chitosan-Modified Capillaries for Rapid ZIKV Detection

Abstract

The outbreak of Zika virus (ZIKV) has posed a great challenge to public health in recent years. To address the urgent need of ZIKV RNA assays, we integrate the microfluidic chip embedded with chitosan-modified silicon dioxide capillaries, smartphone-based detection unit to be a C3-system for the rapid extraction and detection of ZIKV RNA. The C3-system is characterized by: (1) four chitosan-modified silicon dioxide capillaries integrated in the microfluidic chip for target ZIKV RNA enrichment and “in situ PCR” (polymerase chain reaction) amplification; (2) smartphone-based point of care (POC) device consisting of a pneumatic subsystem for controlling the nucleic acid extraction processes in the microfluidic chip, a heating subsystem for sample lysis and PCR amplification, and an optical subsystem for signal acquisition. The entire detection processes including sample lysis, ZIKV RNA enrichment, and reverse-transcription polymerase chain reaction (RT-PCR) is achieved in the microfluidic chip. Moreover, PCR buffers can be directly loaded into the chitosan-modified silicon dioxide capillaries for “in situ PCR”, in which the captured ZIKV RNA is directly used for downstream PCR without any loss. ZIKV RNA extracted by the C3-system can be successfully recovered at very low concentrations of 50 transducing units (TU)/mL from crude human saliva. This means that our method of detecting viremia in patients infected with ZIKV is reliable.

Advances in point-of-care nucleic acid extraction technologies for rapid diagnosis of human and plant diseases

“…As a result, nucleic acid extraction from saliva is relatively simple and less tedious compared to other body fluids. Several miniaturized systems using saliva as a diagnostic fluid have been developed ( Chen et al, 2010 ; Wand et al, 2018 ; H. Yang et al, 2018 ; Zhu et al, 2020 ). These integrated systems utilized SPE ( Chen et al, 2010 , 2013 ; H. Yang et al, 2018 ), paper-based extraction ( Jiang et al, 2018 ; Seok et al, 2019 ; R. Tang et al, 2017a ), or pH-responsive polymer-based extraction ( Zhu et al, 2020 ) for rapid sample preparation from saliva (also see Table 2 ).…”

“…(f) Schematic illustration of a Zika virus detection chip embedded with chitosan-modified capillaries to capture viral RNA from saliva (reproduced with permission from Ref. ( Zhu et al, 2020 ), © MDPI 2020). …”

“…4 e). Zhu et al (2020) developed a microfluidic device embedded with chitosan-modified capillaries for the rapid extraction of Zika RNA from saliva ( Fig. 4 f).…”

“…However, conventional qPCR requires bulky, expensive, and sophisticated instruments. Alternatively, amplicon detection can also been achieved on cost-effective smartphone-based reader devices ( Borysiak et al, 2015 ; Choi et al, 2016 ; Kaur et al, 2019 ; Ma et al, 2019 ; Wang et al, 2020 ; Zhu et al, 2020 ). Smartphone-based nucleic acid detection platforms have been used for rapid screening of both human and plant diseases in resource-limited settings ( Hernández-Neuta et al, 2019 ; Kong et al, 2017 ).…”

Editorial for the Special Issue on Point-of-Care Devices

“…However, some challenges such as weak reproducibility, instability and lack of multiplexing capability are yet to be addressed to translate the technologies into practical applications.Several research articles have reported the development of chip-, paper-, and nanomaterial-based POC devices for Zika virus detection, sperm quality assessment, and opto-acoustic sensing. Zhu et al [3] developed "C 3 -system", a sample-to-answer microfluidic device for POC detection of Zika virus RNA. This device consists of chitosan-modified silicon dioxide capillaries, a pneumatic unit, a heating unit and a smartphone.…”