Smart gold nanosensor for easy sensing of lead and copper ions in solution and using paper strips

Abstract

A smart gold nanosensor, Au-TA-DNS is designed that can rapidly detect very low concentrations of Pb 2+ and Cu 2+ ions. The nanosensor develops visible blue colour in solution and on paper strips, because of the formation of nanoparticle aggregates upon binding with metal ions. Due to the presence of dansyl fluorophore, Au-TA-DNS also exhibits significant fluorescence quenching following Pb 2+ and Cu 2+ binding in aqueous medium, which is proportional to the concentration of ions. Both colorimetric and fluorometric analyses are very much selective for lead and copper ions with a detection limit of ≤10.0 ppb. The paper based sensing method has the advantage of costeffectiveness and would be useful for wide range of field-test applications such as water quality monitoring process.

A tunable nanopore sensor for the detection of metal ions using translocation velocity and biphasic pulses

“…Such materials can include carbon nanotubes, 1,2 nanorods 3 and nanoparticles of copper 4 , gold, 5 magnetic, 6 and silica. 7 These systems can be designed to produce a signal upon binding to the metal ion or integrated into detection platforms such as atomic adsorption, [8][9][10][11] electrochemical assays, 1,12,13 fluorescence 4,14 and colorimetric sensors 15,16 . Whilst each technology platform has its merits, not all are portable, simple to use/interpret and can require expensive equipment and/or additional gas/carrier liquids.…”

Paper-based sensors and assays: a success of the engineering design and the convergence of knowledge areas

“…30 These concomitant developments in multiple areas have provided a better understanding of the interactions between biomolecules, biomolecules-labels, biomolecules and/or reagents and paper surfaces, as well as, their interaction mechanisms and their exploitation for improving the performance of the devices. Actually, paper-based assays have been widely applied in multiple areas 4,6,18 such as medicine 1,38 (clinical monitoring and diagnosis of diseases), [39][40][41][42] veterinary, 43 food industry, [44][45][46] agriculture/aquaculture, 28,47,48 environmental safety [49][50][51] and security, 45,52,53 for a large range of analytes: drugs, 28,44,45,52 markets of illness 54 (e. g. tumoral biomarkers, [55][56][57] cardiovascular biomarkers 58 ), proteins in corporal fluids (BSA, 41 thrombin 59 ), hormones, 60,61 bacteria, 28,32,[62][63][64] virus, [65][66][67][68] and chemical contaminants 50,…”

“…However, the sensitivity of this technology has increased with the introduction of other methods of detection. Currently, quantitative analytical methods used for paper-based sensors include: colorimetry, 28,[49][50][51] electrochemistry, 55,78,86,87 electroconductivity, 56 fluorescence, 53,72,74,75, PL, 64 CL, 80 ECL, 88 PECL 89,90 nevertheless the use of more sophisticated devices and techniques, like SERS, 91,92 calorimetry, 93 piezoresistive MEMS sensors 94 or electromagnetic resistor 95 are found too. In addition, the detection technologies are being integrated with devices of common use such as cell phones, smartphones, wearable technology, or other imaging devices, scanners, optical drives/disc players, and strip readers.…”

“…In addition, the detection technologies are being integrated with devices of common use such as cell phones, smartphones, wearable technology, or other imaging devices, scanners, optical drives/disc players, and strip readers. Thanks to the advances in nanotechnology and the techniques of electronic microscopy to study the nanostructures and their interaction with biomolecules and chemistry surfaces, NPs of all types have been used in PADs as signal producer to increase the sensitivity, [1][2][3]96 including AuNPs, 45,49,60 AgNPs, 78 carbon NPs, 56,97 latex microspheres, 66,71 liposomes, 48,73 magnetic NPs, 69,98 ceria NPs, 99 QDs, 72,74 up conversion NPs, 68,70,80 (nano)composites such as Eu 3+ onto porous silica, 67 zinc oxide spheres-AgNPs, 55 terbium(III)/gold nanocluster, 75 Fe 2 O 2 -AuNPs 28 combinations of enzymes and NPs (HRP with AuNPs) 100,101 and other materials. In this review we show the state-of-art advances of µPADs as the new generation of paper-based assays, through the analysis of interesting and innovative devices presented in the last eight years.…”

Ultrasensitive indirect competitive ELISA and strip sensor for detection of furazolidone metabolite in animal tissues

“…Enzyme-linked immunosorbent assays (ELISAs) and strip biosensor are characteristic of high sensitivity, low cost, small sample size and high-throughput screening (Bai et al, 2012;Isanga et al, 2017;Nath, Arun, & Chanda, 2015;Peng et al, 2014;Shi, Tian, Wu, Li, & Yu, 2015;Singh, Sharma, & Nara, 2015;Wang et al, 2016;Yu, Su, Zhang, Wei, & Guo, 2017;Zhang et al, 2017). The ELISAs have been widely used for rapid detection of substances such as low molecular analytes, nucleic acids, proteins, etc.…”