Smartphone-Based Device for Colorimetric Detection of MicroRNA Biomarkers Using Nanoparticle-Based Assay

Abstract

The detection of microRNAs (miRNAs) is emerging as a clinically important tool for the non-invasive detection of a wide variety of diseases ranging from cancers and cardiovascular illnesses to infectious diseases. Over the years, miRNA detection schemes have become accessible to clinicians, but they still require sophisticated and bulky laboratory equipment and trained personnel to operate. The exceptional computing ability and ease of use of modern smartphones coupled with fieldable optical detection technologies can provide a useful and portable alternative to these laboratory systems. Herein, we present the development of a smartphone-based device called Krometriks, which is capable of simple and rapid colorimetric detection of microRNA (miRNAs) using a nanoparticle-based assay. The device consists of a smartphone, a 3D printed accessory, and a custom-built dedicated mobile app. We illustrate the utility of Krometriks for the detection of an important miRNA disease biomarker, miR-21, using a nanoplasmonics-based assay developed by our group. We show that Krometriks can detect miRNA down to nanomolar concentrations with detection results comparable to a laboratory-based benchtop spectrophotometer. With slight changes to the accessory design, Krometriks can be made compatible with different types of smartphone models and specifications. Thus, the Krometriks device offers a practical colorimetric platform that has the potential to provide accessible and affordable miRNA diagnostics for point-of-care and field applications in low-resource settings.

The Role of MicroRNAs in HIV Infection

“…They are also often dysregulated in disease and could make promising biomarkers, yet in the past, technical issues with miRNA assays posed challenges [57]. Today, many strategies for miRNA assays have been devised, ranging from specifically adapted reverse transcriptase real-time quantitative polymerase chain reaction approaches [58] to smartphone-based devices for noninvasive detection [59]. Another detection method that can be mentioned among the many that have been developed by now is the thermophoretic detection of exosomal miRNAs, highlighting the feasibility of using these circulating miRNAs as biomarkers for early-stage cancer diagnosis [36].…”

NIR Photocontrolled Fluorescent Nanosensor under a Six-Branched DNA Nanowheel-Induced Nucleic Acid Confinement Effect for High-Performance Bioimaging

“…In the past decade, benefiting from the favorable programmability and biocompatibility, DNA nanotechnology has become a promising choice for developing various biosensors. − Compared with colorimetric, , electrochemical, , and mass spectrometry , platforms, fluorescence imaging can intuitively exhibit real in situ photos and thus it is more conducive to conducting biosensing assays in live biosystems (e.g., cells and body). − To promote the detection sensitivity, a wealth of nucleic acid signal amplification strategies, especially the most typical protein enzyme-free catalytic reactions are proposed to confront the measurements of low-abundance targets. − Despite much effort the current DNA nanotechnology-based bioimaging methods still suffer from the following challenges.…”

Colorimetric Sensors: Methods and Applications

“…Colorimetric sensors have attracted considerable attention in many sensing applications because of their specificity, high sensitivity, cost-effectiveness, ease of use, rapid analysis, simplicity of operation, and clear visibility to the naked eye [ 1 ]. A number of colorimetric sensors have been developed for the detection of metal and non-metal ions [ 2 , 3 ], proteins [ 4 ], small molecules [ 5 , 6 ], gases [ 7 ], viruses and bacteria [ 8 , 9 ], DNA/RNA [ 10 , 11 , 12 ], reactive oxygen species and acidity/base [ 13 ], as well as the biomarkers in clinical diagnostics [ 14 , 15 , 16 ]. However, the complex compositions of various samples and the low content of analytes make it critical to develop sensing tools with high sensitivity and selectivity.…”