Prospects of Nanotechnology in Clinical Immunodiagnostics

Nanostructured materials are promising compounds that offer new opportunities as sensing platforms for the detection of biomolecules. Having micrometer-scale length and nanometer-scale diameters, nanomaterials can be manipulated with current nanofabrication methods, as well as self-assembly techniques, to fabricate nanoscale bio-sensing devices. Nanostructured materials possess extraordinary physical, mechanical, electrical, thermal and multifunctional properties. Such unique properties advocate their use as biomimetic membranes to immobilize and modify biomolecules on the surface of nanoparticles. Alignment, uniform dispersion, selective growth and diameter control are general parameters which play critical roles in the successful integration of nanostructures for the fabrication of bioelectronic sensing devices. In this review, we focus on different types and aspects of nanomaterials, including their synthesis, properties, conjugation with biomolecules and their application in the construction of immunosensing devices. Some key results from each cited article are summarized by relating the concept and mechanism behind each sensor, experimental conditions and the behavior of the sensor under different conditions, etc. The variety of nanomaterial-based bioelectronic devices exhibiting novel functions proves the unique properties of nanomaterials in such sensing devices, which will surely continue to expand in the future. Such nanomaterial based devices are expected to have a major impact in clinical immunodiagnostics, environmental monitoring, security surveillance and for ensuring food safety

Nano-lantern on paper for smartphone-based ATP detection

ATP-driven bioluminescence relying on the D-luciferin-luciferase reaction is widely employed for several biosensing applications where bacterial ATP detection allows to verify microbial contamination for hygiene monitoring in hospitals, food processing and in general for cell viability studies. Several ATP kit assays are already commercially available but an user-friendly ATP biosensor characterized by low-cost, portability, and adequate sensitivity would be highly valuable for rapid and facile on site screening. Thanks to an innovative freeze-drying procedure, we developed a user-friendly, ready-to-use and stable ATP sensing paper biosensor that can be combined with smartphone detection. The ATP sensing paper includes a lyophilized \u201cnano-lantern\u201d with reaction components being rapidly reconstituted by 10 \u3bcL sample addition, enabling detection of 10 1214 mol of ATP within 10 min. We analysed urinary microbial ATP as a biomarker of urinary tract infection (UTI), confirming the capability of the ATP sensing paper to detect the threshold for positivity corresponding to 105 colony-forming units of bacteria per mL of urine

Simple On-plastic/paper Inkjet-printed Solid-state Ag/agcl Pseudoreference Electrode

A miniaturized, disposable, and low cost Ag/AgCl pseudoreference electrode based on inkjet printing has been developed. Silver ink was printed and chlorinated with bleach solution. The reference electrodes obtained in this work showed good reproducibility and stability during at least 30 min continuous measurement and even after 30 days storage without special care. Moreover, the strategy used in this work can be useful for large scale production of a solid-state Ag/AgCl pseudoreference electrode with different designs and sizes, facilitating the coupling with different electrical/electrochemical microsensors and biosensors.86211053110534Mroz, A., Borchardt, M., Diekmann, C., Cammann, K., Knoll, M., Dumschat, C., (1998) Analyst, 123, pp. 1373-1376Wongkaew, N., Kirschbaum, S.E.K., Surareungchai, W., Durst, R.A., Baeumner, A.J., (2012) Electroanalysis, 24 (10), pp. 1903-1908Zhou, J., Ren, K., Zheng, Y., Su, J., Zhao, Y., Ryan, D., Wu, H., (2010) Electrophoresis, 31, pp. 3083-3089Kakiuchi, T., Yoshimatsu, T., Nishi, N., (2007) Anal. Chem., 79, pp. 7187-7191Noh, J., Park, S., Boo, H., Kim, H.C., Chung, T.D., (2011) Lab Chip, 11, pp. 664-671Vonau, W., Oelßner, W., Guth, U., Henze, J., (2010) Sens. Actuators, B, 144, pp. 368-373Thomas, H., Heide, R., Terfort, A., (2012) Sens. Actuators, B, 171-172, pp. 155-164Mousavi, Z., Granholm, K., Sokalski, T., Lewenstam, A., (2013) Analyst, 138, pp. 5216-5220Lan, W.-J., Maxwell, E.J., Parolo, C., Bwambok, D.K., Subramaniam, A.B., Whitesides, G.M., (2013) Lab Chip, 13, pp. 4103-4108Rattanarat, P., Dungchai, W., Cate, D., Volckens, J., Chailapakul, O., Henry, C.S., (2014) Anal. Chem., 86, pp. 3555-3562Rivas, L., Escosura-Muñiz, A., Pons, J., Merkoçi, A., (2014) Electroanalysis, 26, pp. 1287-1294Kamyshny, A., Steinke, J., Magdassi, S., (2011) Open Appl. Phys. J., 4, pp. 19-36Kralovaa, M., Dzika, P., Veselya, M., Cihlar, J., (2014) Catal. Today, 230, pp. 188-196Tang, W., Feng, L., Zhao, J., Cui, Q., Chen, S., Guo, X., (2014) J. Mater. Chem. C, 2, pp. 1995-2000Jin, X., Lu, J., Liu, P., Tong, H., (2003) J. Electroanal. Chem., 542, pp. 85-96Maattanen, A., Vanamo, U., Ihalainen, P., Pulkkinen, P., Tenhu, H., Bobacka, J., Peltonen, J., (2013) Sens. Actuators, B, 177, pp. 153-162Dickinson, J.W., Bromley, M., Andrieux, F.P.L., Boxall, C., (2013) Sensors, 13, pp. 3635-3651Ha, H., Payer, J., (2011) Electrochim. Acta, 56, pp. 2781-2791Kim, Y.H., Sachse, C., Machala, M.L., May, C., Muller-Meskamp, L., Leo, K., (2011) Adv. Funct. Mater., 21, pp. 1076-1081Li, J.T., Ye, F., Vaziri, S., Muhammed, M., Lemme, M.C., Ostling, M., (2013) Adv. Mater., 25, pp. 3985-3992Sánchez, M.M., Domingo, C.M., Ramon, E., Merkoçi, A., (2014) Adv. Funct. Mater

Experimental Comparison in Sensing Breast Cancer Mutations by Signal on and Signal off Paper-Based Electroanalytical Strips

The development of paper-based electroanalytical strips as powerful diagnostic tools has gained a lot of attention within the sensor community. In particular, the detection of nucleic acids in complex matrices represents a trending topic, especially when focused toward the development of emerging technologies, such as liquid biopsy. DNA-based biosensors have been largely applied in this direction, and currently, there are two main approaches based on target/probe hybridization reported in the literature, namely Signal ON and Signal OFF. In this technical note, the two approaches are evaluated in combination with paper-based electrodes, using a single strand DNA relative to H1047R (A3140G) missense mutation in exon 20 in breast cancer as the model target. A detailed comparison among the analytical performances, detection protocol, and cost associated with the two systems is provided, highlighting the advantages and drawbacks depending on the application. The present work is aimed to a wide audience, particularly for those in the field of point-of-care, and it is intended to provide the know-how to manage with the design and development stages, and to optimize the platform for the sensing of nucleic acids using a paper-based detection method

One-Step Laser Nanostructuration of Reduced Graphene Oxide Films Embedding Metal Nanoparticles for Sensing Applications

The combination of two-dimensional materials and metal nano-particles (MNPs) allows the fabrication of novel nanocomposites with unique physical/chemical properties exploitable in high-performance smart devices and biosensing strategies. Current methods to obtain graphene-based films decorated with noble MNPs are cumbersome, poorly reproducible, and difficult to scale up. Herein, we propose a straightforward, versatile, surfactant-free, and single-step technique to produce reduced graphene oxide (rGO) conductive films integrating "naked" noble MNPs. This method relies on the instantaneous laser-induced co-reduction of graphene oxide and metal cations, resulting in highly exfoliated rGO nanosheets embedding gold, silver, and platinum NPs. The production procedure has been optimized, and the obtained nanomaterials are fully characterized; the hybrid nanosheets have been easily transferred onto lab-made screen-printed electrodes preserving their nanoarchitecture. The Au@rGO-, Ag@rGO-, and Pt@ rGO-based electrodes have been challenged to detect caffeic acid, nitrite, and hydrogen peroxide in model solutions and real samples. The sensors yielded quantitative responses (R2 >= 0.997) with sub-micromolar limits of detections (LODs <= 0.6 mu M) for all the analytes, allowing accurate quantification in samples (recoveries >= 90%; RSD <= 14.8%, n = 3). This single-step protocol which requires low cost and minimal equipment will allow the fabrication of free-standing, MNP-embedded rGO films integrable into a variety of scalable smart devices and biosensors

Toward Nanotechnology-Enabled Approaches against the COVID-19 Pandemic

The COVID-19 outbreak has fueled a global demand for effective diagnosis and treatment as well as mitigation of the spread of infection, all through large-scale approaches such as specific alternative antiviral methods and classical disinfection protocols. Based on an abundance of engineered materials identifiable by their useful physicochemical properties through versatile chemical functionalization, nanotechnology offers a number of approaches to cope with this emergency. Here, through a multidisciplinary Perspective encompassing diverse fields such as virology, biology, medicine, engineering, chemistry, materials science, and computational science, we outline how nanotechnology-based strategies can support the fight against COVID-19, as well as infectious diseases in general, including future pandemics. Considering what we know so far about the life cycle of the virus, we envision key steps where nanotechnology could counter the disease. First, nanoparticles (NPs) can offer alternative methods to classical disinfection protocols used in healthcare settings, thanks to their intrinsic antipathogenic properties and/or their ability to inactivate viruses, bacteria, fungi, or yeasts either photothermally or via photocatalysis-induced reactive oxygen species (ROS) generation. Nanotechnology tools to inactivate SARS-CoV-2 in patients could also be explored. In this case, nanomaterials could be used to deliver drugs to the pulmonary system to inhibit interaction between angiotensin-converting enzyme 2 (ACE2) receptors and viral S protein. Moreover, the concept of "nanoimmunity by design"can help us to design materials for immune modulation, either stimulating or suppressing the immune response, which would find applications in the context of vaccine development for SARS-CoV-2 or in counteracting the cytokine storm, respectively. In addition to disease prevention and therapeutic potential, nanotechnology has important roles in diagnostics, with potential to support the development of simple, fast, and cost-effective nanotechnology-based assays to monitor the presence of SARS-CoV-2 and related biomarkers. In summary, nanotechnology is critical in counteracting COVID-19 and will be vital when preparing for future pandemics