A fluorescence chemosensor based on peptidase for detecting nickel(II) with high selectivity and high sensitivity

Abstract

We report herein a new class of metal ion chemosensors and give the first example of a metal-dependent peptidase chemosensor for metal ions. The chemosensor contains the basic specific Ni(II)-dependent peptide bond hydrolysis sequence (Gly-Ala-Ser-Arg-His-Trp-Lys-Phe-Lys). The substrate was labeled with a fluorophore at the N-terminal and a quencher at the C-terminal Lys side chain. Initially, the MOCAc ((7-methoxycoumarin-4-yl)acetyl-) emission was quenched by the nearby quencher. In the presence of Ni(II), the substrate was irreversibly cleaved at the cleavage site, leading to a 20-fold increase in fluorescence intensity. The chemosensor combines the high selectivity of a peptidase (at least greater than tenfold for Ni(II) over other metal ions) with the high sensitivity of fluorescence detection limit of 50 nM and can be applied for the quantitative detection of Ni(II) over a concentration range of three orders of magnitude. Given this degree of selectivity and sensitivity, our molecular engineering design may prove useful in the future development of other peptidase-based probes for different metal ions in toxicological and environmental monitoring.

Colorimetric chemosensor for Ni2+ based on alizarin complexone and a cationic polyelectrolyte in aqueous solution

“…From k and σ (4.50 × 10 −4 ), the detection limit was calculated to 0.37 μM, which was lower than the drinking water guideline (0.68 μM) recommended by the U.S. Environmental Protection Agency (U.S. EPA). 61 The detection limit was comparable to those (0.057-0.48 μM) of other colorimetric chemosensors for Ni 2+ in aqueous solution. 33,62 Thus, the ALC and PDADMAC mixture can be a good colorimetric chemosensor for the quantification of Ni 2+ in aqueous solution.…”

“…The slope ( k value) of a straight line was obtained to be 3.65 × 10 3 ( R 2 = 0.9960). From k and σ (4.50 × 10 −4 ), the detection limit was calculated to 0.37 μM, which was lower than the drinking water guideline (0.68 μM) recommended by the U.S. Environmental Protection Agency (U.S. EPA) . The detection limit was comparable to those (0.057–0.48 μM) of other colorimetric chemosensors for Ni 2+ in aqueous solution .…”

Metal assisted peptide bond hydrolysis: Chemistry, biotechnology and toxicological implications

“…This reaction also gave rise to other emerging applications. It was utilized in FRET-based sensors for detection of Ni 2+ and Cu 2+ ions in water [148,149]. It was also applied in organic synthesis to generate active thioesters as building blocks for protein engineering [150].…”

Multiuse Nanopore Platform with Disposable Paper Analytical Device for the Detection of Heavy Metal Ions

“…Alternative techniques have been developed allowing the simple, rapid, and onsite detection of metal ions. Examples of such sensors include the use of colorimetric, − fluorescence, − and electrochemical sensors. , Paper-based analytical devices (PADs) are an area of increasing interest due to their low cost, viable mass production, ease of fabrication and modification, and ease of disposability. ,, …”