Nanomaterials are currently implemented as state-of-the-art tools in biological detection applications thanks to their intrinsic capability to access the biological entities (viruses, bacteria, cells, proteins, DNA...) at different scales of spatial resolution down to nanometer range, capturing and transducing information about physicochemical properties of those systems. They can detect very low content of disease markers or DNA fragments present in human body fluids, favouring the arrival of an early disease diagnosis and personalized therapies in a very near future.
An international team of researchers at the Institute for microelectronics and microsystem of the National Research Council of Italy (Cnr-Imm, Rome) and at the Department of Mechanical Engineering of Johns Hopkins University (Baltimore, USA) has developed an highly sensitive and label-free sensor for the detection of glycated albumin (GA), a novel robust molecular biomarker for screening and monitoring of diabetes mellitus, by leveraging the diagnostic potential of silver-coated silicon nanowires with a disordered arrangement.
The research has been stimulated by the urgent need of innovative diagnostic tools to detect the diabetes mellitus in patients with anemia or hemoglobinopathies, or chronic kidney disease, for whom the usually quantified glycated hemoglobin (HbA1c) level may be inaccurate. GA is a non-traditional glycemic marker, alternative to HbA1c and very useful as diabetes indicator in case of hematologic disorders, and for conditions in which glycemia changes rapidly, such as during assessment and optimization of a diabetic patient's treatment regime. The biosensor developed by the researchers of the CNR-Imm (Dr. Annalisa Convertino, Dr. Valentina Mussi and Dr. Luca Maiolo) and Department of Mechanical Engineering of the Johns Hopkins University (Prof. Ishan Barman and Dr. Debadrita Paria) exploits the reduced dimensionality of the nanowires and their disordered arrangement, which allow at the same time to trap the target biomolecules and generate an enhancement of the electromagnetic field in the contact points between neighbouring and crossing wires, amplifying the Raman signal used for the detection of the biological sample dispersed in the matrix. The results have been published on Advanced Healthcare Materials and pave the way toward a rapid, predictive and alternative diagnostic approach of the diabetes mellitus.
The research has been partially supported by joint research project “Scalable nano-plasmonic platform for differentiation and drug response monitoring of organ-tropic metastatic cancer cells” (US19GR07), coordinated by Dr. Annalisa Convertino and funded by the Italian Minister of Foreign Affairs and International Collaboration (MAECI) within the Scientific and Collaboration Program Italy-USA/2019-2021.
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