Electroanalytical Sensor Based on Gold-Nanoparticle-Decorated Paper for Sensitive Detection of Copper Ions in Sweat and Serum

Abstract

The growth of (bio)­sensors in analytical chemistry is mainly attributable to the development of affordable, effective, portable, and user-friendly analytical tools. In the field of sensors, paper-based devices are gaining a relevant position for their outstanding features including foldability, ease of use, and instrument-free microfluidics. Herein, a multifarious use of filter paper to detect copper ions in bodily fluids is reported by exploiting this eco-friendly material to (i) synthesize AuNPs without the use of reductants and/or external stimuli, (ii) print the electrodes, (iii) load the reagents for the assay, (iv) filter the gross impurities, and (v) preconcentrate the target analyte. Copper ions were detected down to 3 ppb with a linearity up to 400 ppb in standard solutions. The applicability in biological matrices, namely, sweat and serum, was demonstrated by recovery studies and by analyzing these biofluids with the paper-based platform and the reference method (atomic absorption spectroscopy), demonstrating satisfactory accuracy of the novel eco-designed analytical tool.

Engineered Bacterial Cellulose Nanostructured Matrix for Incubation and Release of Drug-Loaded Oil in Water Nanoemulsion

“…First of all, the scale bar of the image was measured by using the scale option after using the zoom option from the toolbar. SEM images (1024 × 768 pixels) were obtained, as already described ( Di Natale et al, 2019 ; Bagheri et al, 2021 ; Di Natale et al, 2021a ; Di Natale et al, 2021b ; Di Natale et al, 2021c ; Di Natale et al, 2021d ; Florio et al, 2021 ; Di Natale et al, 2020a ; Di Natale et al, 2020b ; La Manna et al, 2021a ; La Manna et al, 2021b ), and then segmented using the algorithms provided by “DiameterJ Segment” to convert the image into binary forms. Then, segmented images were processed by DiameterJ to measure the diameter of the cellulose bundles and fibers.…”

Origami Paper-Based Electrochemical (Bio)Sensors: State of the Art and Perspective

“…Indeed, besides being plastic free, paper sensors are able to: Reduce the use of energy consumption (for instance, using the capillarity for the microfluidics instead of an external pump) [ 3 ]; Reduce chemicals (since the reaction can happen in the few μL solution layer within the cellulose network) [ 4 ]; Reduce or avoid the sample treatment by exploiting the porosity of the paper [ 5 ]; Allow for the paper network as reservoir for modifying the sensors with nanomaterials [ 6 , 7 ]; Deliver reagent-free analytical tools by exploiting the porosity of the paper [ 8 , 9 ]; Carry out easily the multiplex analyses [ 10 ]; Increase the sensitivity by multistep of sample loading and waiting to become dry before exploiting the 3D network of the paper [ 11 ]; Overcome the limitation of alumina or polyester-based sensors (by measuring the analytes in gas phase of surface, without any additional external sampling system) [ 12 , 13 , 14 ]. …”

“…Reduce or avoid the sample treatment by exploiting the porosity of the paper [5]; • Allow for the paper network as reservoir for modifying the sensors with nanomaterials [6,7]; • Deliver reagent-free analytical tools by exploiting the porosity of the paper [8,9]; • Carry out easily the multiplex analyses [10]; • Increase the sensitivity by multistep of sample loading and waiting to become dry before exploiting the 3D network of the paper [11]; • Overcome the limitation of alumina or polyester-based sensors (by measuring the analytes in gas phase of surface, without any additional external sampling system) [12][13][14].…”

Electrochemical Biosensors for Tracing Cyanotoxins in Food and Environmental Matrices

“…For these reasons, an alternative to traditional assays is represented by biosensors, which are simple, economical and efficient tools for detecting plethora of pollutants, including natural toxins [ 36 , 37 , 38 ]. Among the different strategies that have been employed for cyanotoxins detection using biosensors, e.g., colorimetric, electrochemical, fluorescence, plasmonic, the electrochemical ones have appeared as the most suitable for decentralized monitoring due to their unique features such as miniaturization, high compatibility with portable commercial readers (e.g., PalmSens developed a smartphone-powered potentiostat) and being not affected by colored/opaque matrices [ 39 , 40 , 41 ]. Electrochemical approaches have been highly powered by the adoption of nanomaterials and synthetic recognition probes (e.g., aptamers), which have been able to manufacture highly sensitive and specific platforms for handheld monitoring.…”