Nanoarchitectures based on multi-walled carbon nanotubes non-covalently functionalized with Concanavalin A: A new building-block with supramolecular recognition properties for the development of electrochemical biosensors

We propose an innovative nanoarchitecture for the development of electrochemical biosensors based on the non-covalent functionalization of multi-walled carbon nanotubes (MWCNTs) with the lectin Concanavalin A (ConA) and the site-specific supramolecular binding of glycobiomolecules. As proof-of-concept, we propose the use of two glycoenzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), for building mono and bienzymatic glucose biosensors. The selected conditions for the preparation of the dispersion were 1.5 mg MWCNTs in 1.0 mL of 2.0 mg mL −1 ConA sonicated for 5.0 min with sonicator probe. The monoenzymatic glucose biosensor was prepared by casting GCE with the MWCNTs-ConA dispersion (GCE/MWCNTs-ConA) followed by the interaction with GOx (GCE/MWCNTs-ConA/GOx), while the bienzymatic one was obtained by interaction of GCE/MWCNTs-ConA with GOx + HRP (GCE/MWCNTs-ConA/GOx-HRP). The best analytical performance was obtained with the bienzymatic biosensor from the amperometric response at -0.050 V in the presence of 1.0 × 10 -4 M hydroquinone. The sensitivity was (2.22 ± 0.03) μA mM −1 (which was 5.2 times higher than the one obtained with the monoenzymatic biosensor) and a detection limit of 0.31 μM. The reproducibility was 5.4% and the biosensor was challenged with human blood serum showing an excellent correlation with the values reported by the laboratory.Fil: Ortiz, Elvis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Autónoma Metropolitana Iztapalapa; MéxicoFil: Gallay, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Galicia, Laura. Universidad Autónoma Metropolitana Iztapalapa; MéxicoFil: Eguílaz Rubio, Marcos. Universidad Autónoma Metropolitana Iztapalapa; MéxicoFil: Rivas, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Fully Integrated Biochip Platforms for Advanced Healthcare

Recent advances in microelectronics and biosensors are enabling developments of innovative biochips for advanced healthcare by providing fully integrated platforms for continuous monitoring of a large set of human disease biomarkers. Continuous monitoring of several human metabolites can be addressed by using fully integrated and minimally invasive devices located in the sub-cutis, typically in the peritoneal region. This extends the techniques of continuous monitoring of glucose currently being pursued with diabetic patients. However, several issues have to be considered in order to succeed in developing fully integrated and minimally invasive implantable devices. These innovative devices require a high-degree of integration, minimal invasive surgery, long-term biocompatibility, security and privacy in data transmission, high reliability, high reproducibility, high specificity, low detection limit and high sensitivity. Recent advances in the field have already proposed possible solutions for several of these issues. The aim of the present paper is to present a broad spectrum of recent results and to propose future directions of development in order to obtain fully implantable systems for the continuous monitoring of the human metabolism in advanced healthcare applications

Doble role of bathocuproine disulfonic acid as multi-walled carbon nanotubes dispersing agent and copper preconcentration ligand: Analytical applications for the development of hydrogen peroxide and glucose electrochemical sensors

We are reporting a new strategy for preparing carbon nanotubes (CNTs)-based hydrogen peroxide and glucose amperometric sensors by taking advantage of the dual role of bathocuproine disulfonic acid (BCS) as dispersing agent of multi-walled carbon nanotubes (MWCNTs) and as ligand for the preconcentration of Cu(II). The platform was obtained by casting glassy carbon electrodes (GCE) with the dispersion of MWCNTs in BCS (MWCNTs-BCS) followed by the preconcentration of Cu(II) by surface complex formation at open circuit potential (GCE/MWCNTs-BCS/Cu). The resulting electrode was used for the sensitive amperometric quantification of hydrogen peroxide at 0.400 V catalyzed by the preconcentrated copper, with a linear range between 5.0 × 10−7 and 7.4 × 10-6 M, a sensitivity of 24.3 mA.M-1, and a detection limit of 0.2 μM. The adsorption of GOx at GCE/MWCNTs-BCS/Cu followed by the immobilization of Nafion (Naf), allowed the construction of a sensitive and selective amperometric glucose biosensor with a linear range between 5.0 × 10-6 M and 4.9 × 10-4 M, a sensitivity of (477 ± 3) μA.M-1 and a detection limit of 2 μM. The proposed (bio)sensors were successfully used for the quantification of hydrogen peroxide in enriched milk samples and glucose in milk and commercial beverages without any pretreatment.Fil: Gallay, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Rodriguez, Marcela Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Eguílaz Rubio, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Rivas, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

d-(+)-Galactose-Conjugated Single-Walled Carbon Nanotubes as New Chemical Probes for Electrochemical Biosensors for the Cancer Marker Galectin-3

d-(+)-Galactose-conjugated single-walled carbon nanotubes (SWCNTs) were synthesized for use as biosensors to detect the cancer marker galectin-3. To investigate the binding of galectin-3 to the d-(+)-galactose-conjugated SWCNTs, an electrochemical biosensor was fabricated by using molybdenum electrodes. The binding affinities of the conjugated SWCNTs to galectin-3 were quantified using electrochemical sensitivity measurements based on the differences in resistance together with typical I-V characterization. The electrochemical sensitivity measurements of the d-(+)-galactose-conjugated SWCNTs differed significantly between the samples with and without galectin-3. This indicates that d-(+)-galactose-conjugated SWCNTs are potentially useful electrochemical biosensors for the detection of cancer marker galectin-3

Highly efficient bienzyme functionalized nanocomposite-based microfluidics biosensor platform for biomedical application

This report describes the fabrication of a novel microfluidics nanobiochip based on a composite comprising of nickel oxide nanoparticles (nNiO) and multiwalled carbon nanotubes (MWCNTs), as well as the chip's use in a biomedical application. This nanocomposite was integrated with polydimethylsiloxane (PDMS) microchannels, which were constructed using the photolithographic technique. A structural and morphological characterization of the fabricated microfluidics chip, which was functionalized with a bienzyme containing cholesterol oxidase (ChOx) and cholesterol esterase (ChEt), was accomplished using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy. The XPS studies revealed that 9.3% of the carboxyl (COOH) groups present in the nNiO-MWCNT composite are used to form amide bonds with the NH 2 groups of the bienzyme. The response studies on this nanobiochip reveal good reproducibility and selectivity, and a high sensitivity of 2.2â.mA/mM/cm 2. This integrated microfluidics biochip provides a promising low-cost platform for the rapid detection of biomolecules using minute samples

Nanomaterials towards Biosensing of Alzheimer’s Disease Biomarkers

Alzheimer's disease (AD) is an incurable and highly debilitating condition characterized by the progressive degeneration and/or death of nerve cells, which leads to manifestation of disabilities in cognitive functioning. In recent years, the development of biosensors for determination of AD's main biomarkers has made remarkable progress, particularly based on the tremendous advances in nanoscience and nanotechnology. The unique and outstanding properties of nanomaterials (such as graphene, carbon nanotubes, gold, silver and magnetic nanoparticles, polymers and quantum dots) have been contributing to enhance the electrochemical and optical behavior of transducers while offering a suitable matrix for the immobilization of biological recognition elements. Therefore, optical and electrochemical immuno- and DNA-biosensors with higher sensitivity, selectivity and longer stability have been reported. Nevertheless, strategies based on the detection of multiple analytes still need to be improved, as they will play a crucial role in minimizing misdiagnosis. This review aims to provide insights into the conjugation of nanomaterials with different transducers highlighting their crucial role in the construction of biosensors for detection of AD main biomarkers.This work was financially supported by: project UID/EQU/00511/2019—Laboratory for Process Engineering, Environment, Biotechnology and Energy—LEPABE and project UID/QUI/50006/2019—REQUIMTE, both funded by national funds through FCT/MCTES (PIDDAC); Project POCI-01-0145-FEDER-006939, funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES; Project UID/EQU/00511/2019—Laboratory for Process Engineering, Environment, Biotechnology and Energy—LEPABE funded by national funds through FCT/MCTES (PIDDAC). The PhD grant of Pedro Carneiro (SFRH/BD/131755/2017) is financially supported by the Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

Nanomaterials for Healthcare Biosensing Applications

In recent years, an increasing number of nanomaterials have been explored for their applications in biomedical diagnostics, making their applications in healthcare biosensing a rapidly evolving field. Nanomaterials introduce versatility to the sensing platforms and may even allow mobility between different detection mechanisms. The prospect of a combination of different nanomaterials allows an exploitation of their synergistic additive and novel properties for sensor development. This paper covers more than 290 research works since 2015, elaborating the diverse roles played by various nanomaterials in the biosensing field. Hence, we provide a comprehensive review of the healthcare sensing applications of nanomaterials, covering carbon allotrope-based, inorganic, and organic nanomaterials. These sensing systems are able to detect a wide variety of clinically relevant molecules, like nucleic acids, viruses, bacteria, cancer antigens, pharmaceuticals and narcotic drugs, toxins, contaminants, as well as entire cells in various sensing media, ranging from buffers to more complex environments such as urine, blood or sputum. Thus, the latest advancements reviewed in this paper hold tremendous potential for the application of nanomaterials in the early screening of diseases and point-of-care testing