Double Covalent Coupling Method for the Fabrication of Highly Sensitive and Reusable Electrogenerated Chemiluminescence Sensors

Abstract

A double covalent coupling method for the fabrication of a highly sensitive and reusable electrogenerated chemiluminescence (ECL) chemical sensor for the detection of tertiary amines and ECL aptamer-based (ECL-AB) biosensor for the detection of cocaine is reported. The ECL sensors were constructed by covalent coupling of amino-containing Ru(bpy)(3)(2+) derivatives (Ru1, Ru(bpy)(3)(2+) = tris(2,2'-bipyridyl)ruthenium(II)) or cocaine aptamer-Ru1 to the surface of a paraffin-impregnated graphite electrode that had been covalently modified with a monolayer of 4-aminobenzene sulfonic acid via electrochemical oxidations. ECL performance of the newly developed chemical sensors was evaluated using tri-n-propylamine (TPrA) and metoclopramide (MCP) as model analytes. The sensors exhibited excellent sensitivity, stability, and reproducibility with a detection limit of 30 nM for TPrA and 2.0 nM for MCP, and relative standard deviations (RSDs) of 2.1% over 90 cyclic potential cycles (0 to 1.50 V vs Ag/AgCl) and 2.6% over 45 cycles (0.60 to +1.30 V vs Ag/AgCl) at 400 mV/s for 50 nM TPrA and 200 nM MCP, respectively. For the ECL-AB biosensor, it showed an extremely low detection limit of 10 pM for cocaine, and offered a good selectivity toward cocaine, heroin, and caffeine. This detection limit was about 4-6 orders of magnitude lower than that reported on the basis of alternating current (AC) voltammetry and optical aptamer-based cocaine biosensors. Additionally, the ECL-AB biosensor was highly reusable (RSD = 2.8%, n = 7) and possessed long-term storage stability (96.8% initial ECL recovery over 21 days storage). A binding constant of 4.6 +/- 0.3 x 10(9) M(-1) between cocaine and its aptamer was estimated using an ECL based Langmuir isotherm approach. Wide ranging applications of the presently reported strategy in fabricating various chemical sensors or biosensors are expected.

Preparation of novel optical fibre-based Cocaine sensors using a molecular imprinted polymer approach

“…Limited sensing solutions for Cocaine detection (e.g. aptamer-based biosensors [8][9][10][11]) are in existence but a compact, hand-held monitor utilising stable synthetic molecular receptors does not exist. This set of technologies includes aptamer-based electrochemical detection [8,9], aptamercoated, piezoresistive, microcantilever-based biosensing [10] and an electrogenerated chemiluminescence aptamer-based approach [11].…”

“…aptamer-based biosensors [8][9][10][11]) are in existence but a compact, hand-held monitor utilising stable synthetic molecular receptors does not exist. This set of technologies includes aptamer-based electrochemical detection [8,9], aptamercoated, piezoresistive, microcantilever-based biosensing [10] and an electrogenerated chemiluminescence aptamer-based approach [11]. In addition, Hans and Sigrist [12] are developing a sensor for detecting Cocaine in saliva and high affinity MIP nanoparticles [13] and extraction MIPs [14] for Cocaine have been reported.…”

Design and synthesis of a fluorescent molecular imprinted polymer for use in an optical fibre-based cocaine sensor

“…Sensing solutions for Cocaine detection have been reported, e.g. aptamer-based biosensors [4][5][6][7] and sensors for saliva, 8 but development of a compact, hand-held monitor utilising stable synthetic molecular receptors remains of interest for some specific applications. Optical fibre sensors can provide many advantages over other sensing technologies and these include their lightweight nature, low cost, potential for multiplexing, remote sensing capability, immunity to electromagnetic interference and overall robustness.…”

Computational Design and Fabrication of Optical Fibre Fluorescent Chemical Probes for the Detection of Cocaine

“…Efforts to develop suitable sensors have centred on aptamerbased biosensors using electrochemical detection [2], [3], electrogenerated chemiluminescence [4] and piezoresistive, microcantilever-based sensing [5] as there are relatively few reports in the literature of new sensor designs. Rapid, in situ detection of Cocaine residues is possible using paper spray ionization coupling with ion mobility spectrometry [6].…”