Single‐Layer Radially Compartmentalized Paper Chip (RCP‐Chip) for Rapid Isothermal Multiplex Detection of SARS‐CoV‐2 Gene Targets

• Published in: Advanced Sensor Research Vol. 4; no. 7
• Main Authors: Sukumar, Pavithra, Saleh, Alla, Deliorman, Muhammedin, Qasaimeh, Mohammad A.
• Format: Journal Article
• Language: English
• Published: Wiley-VCH 01.07.2025
• Subjects: AuNP synthesis; colorimetric readout; envelope gene; microfluidics; multiplex detection; nucleocapsid gene; paper‐based molecular diagnostics; RT‐LAMP; SARS‐CoV‐2 RNA
• ISSN: 2751-1219; 2751-1219
• DOI: 10.1002/adsr.70010

The study presents the development of a radially compartmentalized paper chip (RCP‐Chip) designed for the rapid detection of multiple gene targets of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) using reverse transcription loop‐mediated isothermal amplification (RT‐LAMP) assay. The RCP‐Chip features reaction chambers for multiplexing, fluidic resistors to prevent backflow, fluidic ports for excess fluid venting, and an outer ring to contain overflowing fluids, all within a single‐layer cellulose paper platform. Optimization results successfully achieve a color readout sensitivity of 10 copies µL−1 RNA spiked in water (singleplex device) and 2040 copies µL−1 RNA spiked saliva samples (multiplex device). The chip demonstrates the capability to simultaneously detect the envelope (E) and nucleocapsid (N) genes of SARS‐CoV‐2 in a single run. Remarkably, the RCP‐Chip technology enables rapid qualitative amplification of SARS‐CoV‐2 RNA in as little as 4 min using pH‐based assay. It further enhances this visual detection by implementing in situ synthesis of gold nanoparticles (AuNPs) within the single‐layer paper platform, achieving a total assay time of 9 min. The adaptability of RCP‐Chip can extend beyond SARS‐CoV‐2 detection: It can be modified and optimized for detecting gene targets of other microbial pathogens across diverse environments pertaining to cause diseases. The single‐layer RCP‐Chip enables rapid, multiplexed detection of SARS‐CoV‐2 RNA using RT‐LAMP and gold nanoparticle‐enhanced colorimetric readouts. After sample loading, amplification occurs within radially arranged chambers, allowing simultaneous detection of E and N genes. The compact design integrates fluidic control and visual output, delivering qualitative results within minutes for point‐of‐care diagnostics.