Nazente Atceken

Advances in LFAs for infectious diseases include nanomaterial engineering, CRISPR amplification, and multiplex designs for better sensitivity and quantitation. AI/ML enables smartphone-based objective analysis, despite standardization challenges, paving the way for connected PoC diagnostics.

CRISPR-based diagnostic platforms have gained significant momentum in recent years, enabling highly sensitive and specific detection of pathogens and diseases. Due to their practical benefits, these platforms have become widely adopted in point-of-care (PoC) applications. CRISPR-on-chip technology integrates CRISPR-Cas platforms with diverse microfluidic systems, allowing scalability and portable, real-time, and precise biomolecule detection. This approach enhances diagnostic accuracy, reduces processing times, and minimizes the need for complex laboratory infrastructures, unlike in conventional diagnostics. Using CRISPR-Cas enzymes in microfluidic systems, CRISPR-on-chip platforms offer key advantages such as single-molecule sensitivity, multiplex detection, and applicability. However, integration with microfluidics for PoC applications is still poorly understood, despite CRISPR-Cas being widely used. This study reviews recent developments in CRISPR-on-chip-based diagnostics and highlights its potential applications in infectious diseases, biosensors, and personalized medicine. Furthermore, challenges and future perspectives in achieving an ideal diagnostic solution are discussed.

3D-tunable bioreaction reservoirs, automated via a low-cost portable pressure pump, enables point-of-care LAMP-on-chip for disease detection.

Human monkeypox (Mpox) is a zoonotic disease caused by the Monkeypox virus (MPXV). As of 14 August 2024, the World Health Organization (WHO) has declared it a global health emergency. For Mpox, this was the second public health emergency of global significance in the past two years. MPXV belongs to the Poxviridae family and is phylogenetically and epidemically divided into two clades: the Congo Basin (Clade-I) and the West African (Clade-II) clades. Clade-I has been associated with more severe disease progression and higher mortality compared to Clade-II, and thus the differentiation between clades can play an important role in predicting disease prognosis. The LAMP technique has the advantages of not requiring thermal cycling and achieving higher amplification in a shorter time compared to qPCR. Different types of LAMP assays were developed in this study to benefit from these advantages. We report the development of LAMP-1 and LAMP-2 assays using the LAMP method to detect MPXV Clade-I and Clade-II, respectively. The LAMP-1 assay includes both fluorescence and visible colorimetric readout tests developed with sensitivities of 10³ and 10⁷ copies, respectively. For the LAMP-2 assay, a probe-based test utilizing the Novel R-Duplex DARQ probe was developed, offering fluorescence detection at a sensitivity of 10³ copies. As a result, we successfully developed three highly specific molecular diagnostic tests that distinctly differentiate between MPXV clades, delivering essential tools for the precise diagnosis and effective control of Mpox.

Pathogen-specific point-of-care (PoC) diagnostic tests have become an important need in the fight against infectious diseases and epidemics in recent years. PoC diagnostic tests are designed with the following parameters in mind: rapidity, accuracy, sensitivity, specificity, and ease of use. Molecular techniques are the gold standard for pathogen detection due to their accuracy and specificity. There are various limitations in adapting molecular diagnostic methods to PoC diagnostic tests. Efforts to overcome limitations are focused on the development of integrated molecular diagnostics by utilizing the latest technologies available to create the most successful PoC diagnostic platforms. With this point of view, a new generation technology was developed by combining loop-mediated isothermal amplification (LAMP) technology with clustered regularly interspaced short palindromic repeat (CRISPR)-associated (CRISPR-Cas) technology. This integrated approach benefits from the properties of LAMP technology, namely its high efficiency, short turnaround time, and the lack of need for a complex device. It also makes use of the programmable function of CRISPR-Cas technology and the collateral cleavage activity of certain Cas proteins that allow for convenient reporter detection. Thus, this combined technology enables the development of PoC diagnostic tests with high sensitivity, specificity, and ease of use without the need for complicated devices. In this review, we discuss the advantages and limitations of the CRISPR/Cas combined LAMP technology. We review current limitations to convert CRISPR combined LAMP into pathogen-specific PoC platforms. Furthermore, we point out the need to design more useful PoC platforms using microfabrication technologies by developing strategies that overcome the limitations of this new technology, reduce its complexity, and reduce the risk of contamination.

Human tear film, with a flow rate of 1–3 µL/min, is a rich bodily fluid that transmits a variety of metabolites and hormones containing proteins, lipids and electrolytes that provide clues about ocular and systemic diseases. Analysis of disease biomarkers such as proteins, mRNA, enzymes and cytokines in the tear film, collected by noninvasive methods, can provide significant results for sustaining a predictive, preventive and personalized medicine regarding various diseases such as glaucoma, diabetic retinopathy, keratoconus, dry eye, cancer, Alzheimer’s disease, Parkinson’s disease and COVID-19. Electrochemical impedance spectroscopy (EIS) offers a powerful technique for analyzing these biomarkers. EIS detects electrical equivalent circuit parameters related to biorecognition of receptor–analyte interactions on the electrode surface. This method is advantageous as it performs a label-free detection and allows the detection of non-electroactive compounds that cannot be detected by direct electron transfer, such as hormones and some proteins. Here, we review the opportunities regarding the integration of EIS into tear fluid sampling approaches.

Karaca M, et al. Allergy Asthma Immunol Res. 2020 Sep;12(5):806-820. https://doi.org/10.4168/aair.2020.12.5.806