Highly sensitive dendrimer-based nanoplasmonic biosensor for drug allergy diagnosis

Abstract

A label-free biosensing strategy for amoxicillin (AX) allergy diagnosis based on the combination of novel dendrimer-based conjugates and a recently developed nanoplasmonic sensor technology is reported. Gold nanodisks were functionalized with a custom-designed thiol-ending-polyamido-based dendron (d-BAPAD) peripherally decorated with amoxicilloyl (AXO) groups (d-BAPAD-AXO) in order to detect specific IgE generated in patient's serum against this antibiotic during an allergy outbreak. This innovative strategy, which follows a simple one-step immobilization procedure, shows exceptional results in terms of sensitivity and robustness, leading to a highly-reproducible and long-term stable surface which allows achieving extremely low limits of detection. Moreover, the viability of this biosensor approach to analyze human biological samples has been demonstrated by directly analyzing and quantifying specific anti-AX antibodies in patient's serum without any sample pretreatment. An excellent limit of detection (LoD) of 0.6ng/mL (i.e. 0.25kU/L) has been achieved in the evaluation of clinical samples evidencing the potential of our nanoplasmonic biosensor as an advanced diagnostic tool to quickly identify allergic patients. The results have been compared and validated with a conventional clinical immunofluorescence assay (ImmunoCAP test), confirming an excellent correlation between both techniques. The combination of a novel compact nanoplasmonic platform and a dendrimer-based strategy provides a highly sensitive label free biosensor approach with over two times better detectability than conventional SPR. Both the biosensor device and the carrier structure hold great potential in clinical diagnosis for biomarker analysis in whole serum samples and other human biological samples.

In Vitro Diagnostic Testing for Antibiotic Allergy

“…Of note are gold nanodiscs solid phases, functionalized with amoxicilloyl dendrons, that allow nanoplasmonic detection using label-free anti-IgE. Results obtained show a high correlation with ImmunoCAP 42. Besides minimizing patient risk, key advantages of immunoassays are that serum samples can be stored and transported easily and that analysis can be automated.…”

Recent advances in nanoplasmonic biosensors: applications and lab-on-a-chip integration

“…In general terms, although some publications have dealt with this controversy [7,8,11], there is still a lack of convincing studies that confirm whether nanoplasmonics is competitive enough with SPR in terms of surface sensing performance. However, a few recent works demonstrate that sensitivity levels are in the same order of magnitude, although the sensitivity seems to improve and be higher at low analyte concentration in the case of LSPR, both in a competitive assay [12] and in direct approaches [13,14]. This could be partially due to the strong LSPR field confinement of the nanostructures compared to SPR, which becomes more evident at low target concentrations, especially in direct assays.…”

“…A white light source and a small spectrophotometer are used, which somehow hinder complete integration, although both components can be substituted by LEDs and by commercially available miniaturized spectrophotometers, respectively. With a simple microfluidic and LabView-developed software, bioanalytical applications relevant in the clinical field have been developed reaching excellent levels of sensitivity, even when analyzing real clinical samples [13,14]. Expanding the microfluidics to a multiplexed format would place this kind of platform closer to the LOC concept.…”

“…Direct detection in urine was demonstrated, keeping unaltered the LODs compared to buffer conditions, although for the analysis in serum it was necessary a 1:10 dilution factor. Using the same setup, a biosensor for amoxicillin allergy diagnosis has been recently developed [13]. The biosensor detects specific IgEs against the antibiotics that are produced by the immune system and appear in the patient's serum during an allergy outbreak.…”

Incorporation of Ag Nanoparticles Into Micelles. Stability Studies of Self-Organized Nanoparticlesmicelles Structures

“…The excitation of surface plasmons, and distribution pathways of its energy can lead to significant changes in spectral properties of molecules located in close proximity to the metallic surface, leading to increase or decrease in its absorption or fluorescence. This phenomenon is widely used for monitoring of antibody binding kinetics, occurrence of specific chemical reactions and many other purposes [Aslan, Gryczynski, Malicka, Matveeva, Lakowicz & Geddes, 2005;Spadavecchia, Manera, Quaranta, Siciliano, & Rella, 2005;Soler, Mesa-Antunez, Estevez, Ruiz-Sanchez, Otte, Sepulveda, Collado, Mayorga, Torres, Perez-Inestrosa & Lechuga, 2015].…”