Citation: Xie, Y.; Ma, L.; Ling, S.;
Ouyang, H.; Liang, A.; Jiang, Z.
Aptamer-Adjusted Carbon Dot
Catalysis-Silver Nanosol SERS
Spectrometry for Bisphenol A
Detection. Nanomaterials 2022, 12,
1374. https://doi.org/10.3390/
nano12081374
Academic Editors: Ki-Hyun Kim,
Deepak Kukkar and
Alexey Pestryakov
Received: 14 March 2022
Accepted: 15 April 2022
Published: 17 April 2022
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Article
Aptamer-Adjusted Carbon Dot Catalysis-Silver Nanosol SERS
Spectrometry for Bisphenol A Detection
Yuqi Xie
1
, Lu Ma
1
, Shaoming Ling
1
, Huixiang Ouyang
1,2,
*, Aihui Liang
2
and Zhiliang Jiang
2,
*
1
Key Laboratory of Regional Ecological Environment Analysis and Pollution Control in Western
Guangxi (Baise University), Education Department of Guangxi Zhuang Autonomous Region, College of
Chemistry and Environment Engineering, Baise University, Baise 533000, China; xiekey@sina.com (Y.X.);
malulu2022@163.com (L.M.); lingshaoming@sohu.com (S.L.)
2
Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guangxi Normal
University, Guilin 541004, China; ahliang2008@163.com
* Correspondence: huixiang73@163.com (H.O.); zljiang@mailbox.gxnu.edu.cn (Z.J.)
Abstract:
Carbon dots (CDs) can be prepared from various organic (abundant) compounds that are
rich in surfaces with –OH, –COOH, and –NH
2
groups. Therefore, CDs exhibit good biocompatibility
and electron transfer ability, allowing flexible surface modification and accelerated electron transfer
during catalysis. Herein, CDs were prepared using a hydrothermal method with fructose, saccharose,
and citric acid as C sources and urea as an N dopant. The as-prepared CDs were used to catalyze
AgNO
3
–trisodium citrate (TSC) to produce Ag nanoparticles (AgNPs). The surface-enhanced Raman
scattering (SERS) intensity increased with the increasing CDs concentration with Victoria blue B
(VBB) as a signal molecule. The CDs exhibited a strong catalytic activity, with the highest activity
shown by fructose-based CDs. After N doping, catalytic performance improved; with the passivation
of a wrapped aptamer, the electron transfer was effectively disrupted (retarded). This resulted in
the inhibition of the reaction and a decrease in the SERS intensity. When bisphenol A (BPA) was
added, it specifically bound to the aptamer and CDs were released, recovering catalytical activity.
The SERS intensity increased with BPA over the concentration range of 0.33–66.67 nmol/L. Thus, the
aptamer-adjusted nanocatalytic SERS method can be applied for BPA detection.
Keywords: CDs catalysis; aptamer adjust; SERS; BPA
1. Introduction
Because of their high selectivity, high affinity, and low concentration dissociation,
aptamer (Apt) reactions have been widely used in biomedicine, analytical chemistry, and
clinical examination [
1
–
8
]. Through surface-enhanced Raman scattering (SERS), an en-
hanced Raman signal is obtained for the molecules adsorbed on or close to the metal surface
and activated by its local surface plasma resonance (LSPR) [
9
–
13
]. With the development
of nanoparticle preparation technology, SERS substrates have become more flexible and
inexpensive, allowing them to be modified and fixed on slides or optical fibers [
14
,
15
] or
used directly in colloids [
16
]. These advantages have resulted in the widespread use of
SERS nanosubstrates with local surface plasmon effects [
17
–
20
]. In addition, nanocatalysis
has been conducted to generate noble metal nanoparticles. The generated nanoparticles
have been subsequently used as a direct SERS substrate based on the LSPR effect and
subjected to the Apt reaction to establish an analysis platform [21–23].
Carbon dots (CDs) typically exhibit good biocompatibility and have been widely used
as bioimaging probes and biosensors [
24
,
25
]. CDs have different preparation methods
and numerous sources (including carbohydrates, amino acids, and organic acids) that
promote flexible structure modification [
26
–
29
]. In addition, CDs exhibit good electronic
transfer ability and can be used to catalyze redox reactions [
30
–
33
] and to establish analysis
methods. Long groups [
31
] prepared CDs with lampblack followed by reduction with
Nanomaterials 2022, 12, 1374. https://doi.org/10.3390/nano12081374 https://www.mdpi.com/journal/nanomaterials
