Coreactant-Free Dual Amplified Electrochemiluminescent Biosensor Based on Conjugated Polymer Dots for the Ultrasensitive Detection of MicroRNA

Abstract

Generally, electrochemiluminescence (ECL) assays are performed in the presence of a coreactant. The addition of the coreactant in the detection solution would make the ECL system lack sufficient stability. In the case of dissolved oxygen as the coreactant, the unknown concentration of dissolved O 2 would result in an inevitable error and a lack of reproducibility in detection. A coreactant-free ECL assay could overcome the above shortcomings and thus is an ideal choice. In this work, a coreactant-free dual amplified ECL strategy was constructed for ultrasensitive detection of microRNA (miRNA). Here, target-catalyzed hairpin assembly and enzyme-triggered DNA walker recycling amplification were integrated to achieve dual signal amplification. Carboxyl-functionalized poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′-3}-thiadiazole)] (PFBT-COOH) dots were used as luminophores, which displayed prominent ECL performance without adding any coreactants and removing the dissolved O 2 . As a result, the detection of miRNA was achieved, and the linear range was from 10 aM to 5 pM, and the detection limit was low to 3.3 aM. Meanwhile, the practicability of our biosensor was investigated by analyzing the expression of miRNA in cell lysates. The PFBT-COOH dots provided a great platform for constructing coreactant-free ECL biosensors and expanded the application of conjugated polymer dots in clinical analysis.

Polycarbazole and Its Derivatives: Synthesis and Applications. A Review of the Last 10 Years

“…For this they were awarded with the Nobel Prize in 2000 for their research on conductive polymers [ 1 , 2 ]. These materials have induced the development of many applications, such as organic light emitting diodes (OLEDs) [ 3 , 4 , 5 , 6 ], organic field effect transistors (OFETs) [ 7 , 8 , 9 , 10 , 11 ], dye-sensitized solar cells [ 12 , 13 , 14 , 15 , 16 ], photochromic dyes [ 17 , 18 , 19 , 20 , 21 ], batteries [ 22 , 23 , 24 , 25 , 26 ], and electrocatalyst [ 27 , 28 ] or (bio)sensors [ 26 , 29 , 30 , 31 , 32 ]…”

“…For this they were awarded with the Nobel Prize in 2000 for their research on conductive polymers [1,2]. These materials have induced the development of many applications, such as organic light emitting diodes (OLEDs) [3][4][5][6], organic field effect transistors (OFETs) [7][8][9][10][11], dye-sensitized solar cells [12][13][14][15][16], photochromic dyes [17][18][19][20][21], batteries [22][23][24][25][26], and electrocatalyst [27,28] or (bio)sensors [26,[29][30][31][32] field effect transistors (OFETs) [7][8][9][10][11], dye-sensitized solar cells [12][13][14][15][16], photochromic dyes [17][18][19][20][21], batteries …”

Electrogenerated Chemiluminescence and Electroluminescence of N‐Doped Graphene Quantum Dots Fabricated from an Electrochemical Exfoliation Process in Nitrogen‐Containing Electrolytes

“…[20] ECL has been widely used in many applicationsi ncluding immunoassays and analyte detection due to its high sensitivity and wide dynamic range. [21][22][23][24][25][26][27] ECL has also been reported in several light-emitting applications, where solid-state devices utilizing traditional ECL luminophores exhibited highly efficient, low-voltage operation. [28][29][30][31] The first example of ap olymer light-emitting electrochemical cell (LEC) was introduced in 1995.…”

“…Due to the high redox power of these radicals, ECL generated via the coreactant pathway is often enhanced compared to the annihilation route [20] . ECL has been widely used in many applications including immunoassays and analyte detection due to its high sensitivity and wide dynamic range [21–27] . ECL has also been reported in several light‐emitting applications, where solid‐state devices utilizing traditional ECL luminophores exhibited highly efficient, low‐voltage operation [28–31] …”

Application of Zero-Dimensional Nanomaterials in Biosensing

“…As a result, this sensing platform showed a minimum detection limit of 3.3 aM for RNA. These conjugated Pdots provided a good platform for the construction of coreactant-free ECL biosensors and expand the application of Pdots in the clinical analysis (Luo et al, 2019).…”