RESUMEN
With the growing need for portable, compact, low-cost, and efficient biosensors, plasmonic materials hold the promise to meet this need owing to their label-free sensitivity and deep light-matter interaction that can go beyond the diffraction limit of light. In this review, we shed light on the main physical aspects of plasmonic interactions, highlight mainstream and future plasmonic materials including their merits and shortcomings, describe the backbone substrates for building plasmonic biosensors, and conclude with a brief discussion of the factors affecting plasmonic biosensing mechanisms. To do so, we first observe that 2D materials such as graphene and transition metal dichalcogenides play a major role in enhancing the sensitivity of nanoparticle-based plasmonic biosensors. Then, we identify that titanium nitride is a promising candidate for integrated applications with performance comparable to that of gold. Our study highlights the emerging role of polymer substrates in the design of future wearable and point-of-care devices. Finally, we summarize some technical and economic challenges that should be addressed for the mass adoption of plasmonic biosensors. We believe this review will be a guide in advancing the implementation of plasmonics-based integrated biosensors.
RESUMEN
BACKGROUND/AIM: To estimate the prevalence of autoimmune atrophic gastritis (AAG) in the Russian Federation, a systematic screening of asymptomatic healthy adults by non-invasive biomarker testing was conducted. The aim was i) To test the validity of non-invasive serological screening for AAG; ii) to establish the prevalence of AAG among asymptomatic adults. PATIENTS AND METHODS: Altogether, 1,283 asymptomatic, healthy adults (mean age: 38 years) were screened by GastroPanel® test. Those with a biomarker profile indicating AG (n=46) were invited for further examinations; 21 consented to gastroscopy with biopsies classified using the Updated Sydney System and Operative Link to Gastric Atrophy. Blood tests included parietal cell, intrinsic factor and thyroid peroxidase antibodies, and analysis of vitamin B12 and iron. RESULTS: Gastroscopy and biopsies confirmed AG in 20 of the individuals. Parietal cell, intrinsic factor and thyroid peroxidase antibodies were present in five, one and eight individuals, respectively. AAG-associated co-morbidities (iron deficiency and pernicious anemia) were diagnosed in 10 out of 21. The final diagnosis of AAG was made in 15 out of 1,283 subjects (1.2%), of whom four were Helicobacter pylori-positive. When corrected for verification bias (non-attendees in the confirmatory tests; n=25), the adjusted prevalence of AAG was 2.6% (33/1,283). CONCLUSION: AAG prevalence of 2.6% is among the highest reported using non-invasive tests. GastroPanel® is an optimal screening tool, providing the first link in the diagnostic protocol leading to the final diagnosis of this condition. The role of Helicobacter pylori as a trigger of AAG cannot be ruled out.