Fluorescence Array-Based Sensing of Metal Ions Using Conjugated Polyelectrolytes

Abstract

Array-based sensing offers several advantages for detecting a series of analytes with common structures or properties. In this study, four anionic conjugated polyelectrolytes (CPEs) with a common poly(p-pheynylene ethynylene) (PPE) backbone and varying pendant ionic side chains were designed. The conjugation length, repeat unit pattern, and ionic side chain composition were the main factors affecting the fluorescence patterns of CPE polymers in response to the addition of different metal ions. Eight metal ions, including Pb(2+), Hg(2+), Fe(3+), Cr(3+), Cu(2+), Mn(2+), Ni(2+), and Co(2+), categorized as water contaminants by the Environmental Protection Agency, were selected as analytes in this study. Fluorescence intensity response patterns of the four-PPE sensor array toward each of the metal ions were recorded, analyzed, and transformed into canonical scores using linear discrimination analysis (LDA), which permitted clear differentiation between metal ions using both two-dimensional and three-dimensional graphs. In particular, the array could readily differentiate between eight toxic metal ions in separate aqueous solutions at 100 nM. Our four-PPE sensor array also provides a practical application to quantify Pb(2+) and Hg(2+) concentrations in blind samples within a specific concentration range.

Evaluation of Discrimination Performance in Case for Multiple Non-Discriminated Samples: Classification of Honeys by Fluorescent Fingerprinting

“…Adding fluorophores to samples proved to be an efficient way of improving the discrimination performance using fluorescent fingerprinting when the samples are not intensely fluorescent or are not well discriminated by their intrinsic fluorescence [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The discrimination performance should be quantitatively characterized.…”

“…Most fluorimetric fingerprinting classification methods use intrinsic fluorescence of samples [ 1 , 2 ]. A less developed approach is based on adding fluorophores to samples [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], which promises their better discrimination because of the interaction of fluorophore(s) with non-fluorescent components of the sample and corresponding changes in the spectrum. If more than one fluorophore is added to samples, we can talk about fluorescent sensor arrays [ 4 , 5 , 8 , 10 , 11 , 15 , 17 , 20 ].…”

Molecular weight analysis of water-soluble poly(phenylene ethynylene)s using MALDI-TOF MS

“…Synthesis of P1 and P2 followed the method previously reported . P3 and P4 were synthesized via Sonogashira coupling protocol . P5 was synthesized and provided by the Schanze group at the University of Florida .…”

A Fluorescent Sensor Array Based on Heteroatomic Macrocyclic Fluorophores for the Detection of Polluting Species in Natural Water Samples

“…Our group has developed optical sensor arrays for detection of diverse potential treats in water (Lvova et al, 2013 ; Guanais Goncalves et al, 2016 ) and investigated the possibility to employ a multi-transduction approach for monitoring natural waters pollution by transition metals (Lvova et al, 2015 ). Moreover, various modifications such as implementation of nanodots (Jing et al, 2017 ; Wu et al, 2017 ), graphene oxide (Liu et al, 2013 ), nanoparticles (Ambrosi et al, 2015 ; Peng et al, 2018 ), porous anodic aluminum oxide (Wang and Meng, 2017 ) or conjugated electrolytes (Wu et al, 2015 ) templates were employed in previously developed optical sensing systems in order to enhance the fluorescence signal, thus improving the identification of several heavy metal ions.…”