Modular Combination of Proteolysis-Responsive Transcription and Spherical Nucleic Acids for Smartphone-Based Colorimetric Detection of Protease Biomarkers

Abstract

Sensitive and facile detection of biomarkers is essential for early diagnosis and treatment of diseases. To this end, we here proposed a colorimetric protease assay by the modular combination of proteolysis-responsive transcription and spherical nucleic acids (SNAs). In this assay, target protease-mediated proteolysis triggers the synthesis of RNAs by in vitro transcription, which subsequently results in the aggregation of SNAs with remarkable redshifts in the wavelength of surface plasmon resonance-related absorption. As a proof of concept, this assay achieved the sensitive and specific detection of matrix metalloprotease-2 (MMP-2) with a limit of detection of 3.3 pM. Moreover, the applicability of this colorimetric assay can be expanded to other protease biomarkers (e.g., thrombin and hepatitis C virus NS3/4A) by tuning the target-responsive RNA polymerase module. Furthermore, by the immobilization of SNAs on a glass fiber membrane, a test strip that enables the portable detection of target protease with a smartphone was developed. With the use of a mobile application to capture and process the colorimetric signals, this portable detection system allowed for sensitive evaluation of MMP-2 levels in biological and clinical specimens, highlighting its potential in point-of-care diagnosis of diseases.

NIR Laser Integration of Photodetector on 3D Printed Chamber for Colorimetric Biosensing

“…[10,11] Besides, UV-vis spectroscopy analysis offered from spectrometers also gives a representative method for quantifying precise colorimetric sensing signals based on Beer-Lambert Law. [12] Moreover, in order to promote the portability for extended applications, several works have been proposed for simplifying the designs by combining the specific optical designs with digital images captured by smart phones [13][14][15][16][17][18] for colorimetry analysis, [19] or by using optical fibers coated with sensing probes for modulating light intensity for the photodetector (PD). [20,21] These schemes mainly rely on a system with discrete components, a more integrated and intuitive system to combine the sensing-induced light intensity change and the electrical signal reading is still expected.…”

Spherical nucleic acids: Organized nucleotide aggregates as versatile nanomedicine

“…[ 126 ] New methods involved, including novel single nanoparticle, inductively coupled plasma mass spectrometry (SP‐ICPMS) DNA assays, [ 127 ] CRISPR‐based diagnostics (CRISPR‐Dx), [ 128 ] and colorimetric protease assays with modular combinations of protease‐responsive transcripts and SNAs. [ 135 ]…”

“…[ 130 – 132 ] In addition, the colorimetric protease assay mentioned above can sensitively assess biomarker proteins such as matrix metalloproteinase-2 (MMP-2), thrombin, and hepatitis C virus NS3/4A in biological and clinical samples. [ 135 ] This colorimetric method can be made into test paper and detected by portable phones, which has a vast and promising prospect.…”

Nanopapers toward Green Photonic and Optical Applications

“…Colorimetric techniques have been widely developed and exploited in routine analyses for over a century owing to their simplicity, rapidity, cost-effective production, and multi-information output, in addition to facile visualization of the color variation even by naked eyes. − In the last two decades, colorimetric techniques have gathered high discernibility, predominantly as a result of the advances in the miniaturization concept such as paper-based analytical devices (μPAD) and also imaging capturing gadgets. − Taking ascribed significant features of colorimetric methods into account, an imposing growth in the use of colorimetric methods coupled with various substrates (polymers, nanocomposites, paper, etc.) has been perceived, especially in recent years to meet the demands of qualitative and (semi)­quantitative analyses of various (bio)­molecules. − In this context, colorimetric sensing bioplatforms were fabricated by Golmohammadi’s research group benefiting from curcumin as a fascinating phytochemical with known extraordinary chemical and optical properties.…”