All-Integrated and Highly Sensitive Paper Based Device with Sample Treatment Platform for Cd²⁺ Immunodetection in Drinking/Tap Waters

Abstract

Nowadays, the development of systems, devices, or methods that integrate several process steps into one multifunctional step for clinical, environmental, or industrial purposes constitutes a challenge for many ongoing research projects. Here, we present a new integrated paper based cadmium (Cd(2+)) immunosensing system in lateral flow format, which integrates the sample treatment process with the analyte detection process. The principle of Cd(2+) detection is based on competitive reaction between the cadmium-ethylenediaminetetraacetic acid-bovine serum albumin-gold nanoparticles (Cd-EDTA-BSA-AuNP) conjugate deposited on the conjugation pad strip and the Cd-EDTA complex formed in the analysis sample for the same binding sites of the 2A81G5 monoclonal antibody (mAb), specific to Cd-EDTA but not Cd(2+) free, which is immobilized onto the test line. This platform operates without any sample pretreatment step for Cd(2+) detection thanks to an extra conjugation pad that ensures Cd(2+) complexation with EDTA and interference masking through ovalbumin (OVA). The detection and quantification limits found for the device were 0.1 and 0.4 ppb, respectively, these being the lowest limits reported up to now for metal sensors based on paper. The accuracy of the device was evaluated by addition of known quantities of Cd(2+) to different drinking water samples and subsequent Cd(2+) content analysis. Sample recoveries ranged from 95 to 105% and the coefficient of variation for the intermediate precision assay was less than 10%. In addition, the results obtained here were compared with those obtained with the well-established inductively coupled plasma emission spectroscopy (ICPES) and the analysis of certificate standard samples.

Label-Free Colorimetric Detection of Cadmium Ions in Rice Samples Using Gold Nanoparticles

“…However, the practical application is not included in this paper. 22 A new colorimetric method for sensing Cd 2+ has been developed based on the aggregation of AuNPs mediated by the Cd 2+ -aptamer and cationic polymer. The detection limit is as low as 4.6 nM.…”

Highly Sensitive Paper-based Analytical Devices with the Introduction of a Large-Volume Sample via Continuous Flow

“…Thus, pieces of blotting paper were placed in the detection zone in order to generate an active flow, which is similar to the method employed in lateral-flow immunoassay devices. 50 When two types of chromatographic paper were examined, thicker paper (0.92 mm) was more efficient at increasing the flow rate compared with the flow rate using thin paper (0.50 mm). When three pieces of blotting paper were placed at least 6 cm away from the inlet of the PAD, the time to flow 1 mL of a sample solution was reduced to 570 min, which meant that the flow rate was increased roughly 1.5-fold that of spontaneous evaporation.…”

Facile Synthesis of Galactosamine‐Stabilized Gold Nanoparticles with Sensitive Cd2+ Sensing

“…[5,6] However, the World Health Organization (WHO) standard for the maximum allowable level of inorganic Cd 2+ ions in drinking water is no more than 3 ppb (15 nm). [7] Thus, concerns over the safety of drinking water owing to the damage associated with cadmium toxicity and its toxicology have provided the motivation for the development of rapid, specific, cost-effective, and robust tools for monitoring ionic cadmium. Accordingly, great efforts have been devoted to the development of 5656 mended contamination level of the World Health Organization for cadmium in drinking water of 3 ppb (15 nM ).…”

“…[23][24][25] GNPs are used widely as colorimetric probes, mostly because of the analyte-induced aggregation of nanoparticles. [26][27][28] Functionalized gold nanoparticles have been used in the colorimetric detection of heavy-metal ions, [7] biological molecules, [29] and cancer cells. [30] These approaches have exhibited excellent analytical performance with high sensitivity owing to the strong LSPR and excellent selectivity strategically driven by the interactions of the GNPs with their surroundings mainly through electrostatic and hydrogen-bond interactions as well as donor-acceptor chemical reactions, among others.…”

“…[31][32][33][34] López Marzo and co-workers have exploited a new integrated paper-based Cd-EDTA-BSA-GNP (EDTA = ethylenediaminetetraacetic acid, BSA = bovine serum albumen) device, which was able to determine Cd 2+ ions in drinking and tap water with limits of 0.1 and 0.4 ppb, respectively. [7,35] Liu et al reported a multifunctional senor (colorimetric and surface-enhanced Raman scattering) for the detection of Cd 2+ ions with a limit of 100 ppb. [36] More recently, the Bhosale group developed an attractive colorimetric sensor for Cd 2+ ions based on cyclam-decorated GNPs, which form well-defined wheel-like supramolecular-assembled nanostructures in the presence of Cd 2+ ions.…”