Electrochemiluminescence of Supramolecular Nanorods and Their Application in the “On–Off–On” Detection of Copper Ions

Abstract

In this work, an "on-off-on" switch system has been successfully applied through the construction of an electrochemiluminscent biosensor for copper ion (Cu(2+) ) detection based on a new electrochemiluminescence (ECL) emitter of supramolecular nanorods, which was achieved through supramolecular interactions between 3,4,9,10-perylenetetracarboxylic acid (PTCA) and aniline. The initial "signal-on" state with strong and stable ECL emission was obtained by use of the supramolecular nanorods with a new signal amplification strategy involving a co-reaction accelerator. In addition, ECL quencher probes (Fc-NH2 /Cu-Sub/nano-Au) were fabricated by immobilizing aminoferrocene (Fc-NH2 ) on Cu-substrate strand modified Au nanoparticles. The quencher probes were hybridized with the immobilized Cu-enzyme strand to form Cu(2+) -specific DNAzyme. Similarly, the "signal-off" state was obtained by the high quenching effect of Fc-NH2 on the ECL of the excited-state PTCA ((1) PTCA*). As expected, the second "switch-on" state could achieved by incubating with the target Cu(2+) , owing to the Cu(2+) -specific DNAzyme, which was irreversibly cleaved, resulting in the release of the quencher probes from the sensor interface. Herein, on the basis of the ECL intensity changes (ΔIECL ) before and after incubating with the target Cu(2+) , the prepared Cu(2+) -specific DNAzyme-based biosensor was used for the determination of Cu(2+) concentrations with high sensitivity, excellent selectivity, and good regeneration.

Highly Efficient Intramolecular Electrochemiluminescence Energy Transfer for Ultrasensitive Bioanalysis of Aflatoxin M1

“…25 Firstly, the electrode was polished with 0.3 and 0.05 μm alumina powder, respectively, following by rinsing thoroughly with ultrapure water to obtain a mirror-like surface. Then the GCE was coated by 5 μL of 0.5% Nf (0.5% Nf was diluted by adding 10 μL of 5% Nf in 90 μL ethanol) and dried to form a stable film with plenty of negative charges.…”

Evolution of Supramolecular Systems Towards Next-Generation Biosensors

“…This probe used electrostatic interactions and self-assembly to form supramolecular nanoparticles. The limit of detection of this sensor was 138.0 pM in water and 2.6 nM in serum sample (Lee et al, 2018). This sensor is the first example that shows the dual role of a fluorescent probe to detect and inhibit via the recognition process.…”

“…This reversible sensing system was able to be reused to sense a pH range of 3.04–5.25 up to six times. Sonication or rinsing the sensor surface with a solution at a specific pH ( Duan et al, 2015 ), surfactant addition ( Tang et al, 2016 ; Qu et al, 2017b ), or utilization of competitive binding ( Jia et al, 2016 ; Lei et al, 2016 ) are other strategies that have been reported to effectively regenerate supramolecular sensing units.…”

Aggregation-Induced Emission in Electrochemiluminescence: Advances and Perspectives

“…An aqueous solution can detrimentally affect the emissive behavior by acting as an electron or proton acceptor through hydrogen bond formation [23] as well as by promoting the formation of excimers or exciplex [24]. Such limitations have motivated researchers to exploit new approaches to increase the performance of luminophores, such as by employing nanomaterials [25][26][27] and supramolecular aggregates [28,29]. The aggregation-induced emission (AIE) [30][31][32][33][34] and aggregation-induced emission enhancement (AIEE) [35][36][37] phenomena could be considered to be an ideal tool to overcome the limitation exerted by the media.…”