Browsing by Author "Sui, Ning"

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    AuAg nanocages/graphdiyne for rapid elimination and detection of trace pathogenic bacteria
    (Elsevier, 2022-01-10) Bai, Qiang; Luo, Hongyang; Shi, Shugao; Liu, Shen; Wang, Lina; Du, Fanglin; Yang, Zhugen; Zhu, Zhiling; Sui, Ning
    We prepared a biocompatible AuAg nanocages/graphdiyne @ polyethylene glycol (AuAg/GDY@PEG) composite. The combination of AuAg and GDY to obtain a synergistically enhanced photothermal effect, and the antibacterial effect of GDY and AuAg are used in combined anti-infective therapy. The in vitro antibacterial activity of AuAg/GDY@PEG was investigated, showing an impressive broad-spectrum antibacterial activity with the killing rate > 99.999%. Based on the photothermal conversion ability of AuAg/GDY@PEG, a simple photothermal immunoassay for pathogenic bacteria was successfully established. Sandwich immune response was performed on a microporous plate, the microplate containing the antibody binds specifically to the bacterium being tested, which then binds to the material with the antibody on its surface, and the signal was a change in temperature under 808 nm near-infrared light. The limit of detection (LOD) for S. typhimurium detection is 103 CFU mL−1, with a range of 103–107 CFU mL−1. This method is accurate, rapid and low-cost, which can be used for on-site detection of pathogenic bacteria in food.
  • Thumbnail Image
    ItemOpen Access
    Biosensors for rapid detection of bacterial pathogens in water, food and environment
    (Elsevier, 2022-06-28) Nnachi, Raphael Chukwuka; Sui, Ning; Ke, Bowen; Luo, Zhenhua; Bhalla, Nikhil; He, Daping; Yang, Zhugen
    Conventional techniques (e.g., culture-based method) for bacterial detection typically require a central laboratory and well-trained technicians, which may take several hours or days. However, recent developments within various disciplines of science and engineering have led to a major paradigm shift in how microorganisms can be detected. The analytical sensors which are widely used for medical applications in the literature are being extended for rapid and on-site monitoring of the bacterial pathogens in food, water and the environment. Especially, within the low-resource settings such as low and middle-income countries, due to the advantages of low cost, rapidness and potential for field-testing, their use is indispensable for sustainable development of the regions. Within this context, this paper discusses analytical methods and biosensors which can be used to ensure food safety, water quality and environmental monitoring. In brief, most of our discussion is focused on various rapid sensors including biosensors and microfluidic chips. The analytical performances such as the sensitivity, specificity and usability of these sensors, as well as a brief comparison with the conventional techniques for bacteria detection, form the core part of the discussion. Furthermore, we provide a holistic viewpoint on how future research should focus on exploring the synergy of different sensing technologies by developing an integrated multiplexed, sensitive and accurate sensors that will enable rapid detection for food safety, water and environmental monitoring.
  • Thumbnail Image
    ItemOpen Access
    Nitrogen-doped graphdiyne quantum-dots as an optical-electrochemical sensor for sensitive detection of dopamine
    (Elsevier, 2022-04-22) Bai, Qiang; Luo, Hongyang; Yi, Xuetao; Shi, Shugao; Wang, Lina; Liu, Manhong; Du, Fanglin; Yang, Zhugen; Sui, Ning
    Graphdiyne quantum dots (GDQDs) have attracted increasing attentions due to its unique electronic, optical, and electrochemical properties. However, the low conductivity and quantum yield of GDQDs limit their application. Here, nitrogen-doped graphdiyne dots (N-GDQDs) are firstly synthesized by a simple, friendly and one-step hydrothermal method. The N-GDQDs show a maximum emission at 410 nm under the excitation wavelength of 319 nm. The doping N modifies the surface defect of N-GDQDs and further greatly improves their quantum yield (from 14.6% to 48.6%). In addition, the doping N induces a strong electron transport ability and good conductivity of N-GDQDs. Subsequently, the prepared N-GDQDs are used for constructing an optical-electrochemical nanosensor for sensitive and selective detection of dopamine (DA). DA can quench the fluorescence of N-GDQDs by forming a ground-state non-fluorescent complex between phenoxy anions (in PBS solution) in DA and pyridinic N sites of N-GDQDs, which leads to a highly sensitive and selective detection of DA with a limit of detection (LOD) of 0.14 μM and a linear range of 0.32–500 μM. In the electrochemical detection, DA can be oxidized to DA-quinone under the electric field through N-GDQDs/GCE, which shows a big affinity to N-GDQDs. The LOD for DA is 0.02 μM with a linear range of 0.05–240 μM. Finally, the spiked application for DA detection in human serum samples is investigated, the results show that the method has high accuracy. Our work provides a new carbon quantum dots based sensing platform, which shows great potential in practical application.
  • Thumbnail Image
    ItemOpen Access
    Subsequent monitoring of ferric ion and ascorbic acid using graphdiyne quantum dots-based optical sensors
    (Springer, 2020-11-16) Bai, Qiang; Zhang, Chaoyang; Li, Long; Zhu, Zhiling; Wang, Lina; Jiang, Fuyi; Liu, Manhong; Wang, Zhaobo; Yu, William W.; Du, Fanglin; Yang, Zhugen; Sui, Ning
    Graphdiyne (GDY) as an emerging carbon nanomaterial has attracted increasing attention because of its uniformly distributed pores, highly π-conjugated, and tunable electronic properties. These excellent characteristics have been widely explored in the fields of energy storage and catalysts, yet there is no report on the development of sensors based on the outstanding optical property of GDY. In this paper, a new sensing mechanism is reported built upon the synergistic effect between inner filter effect and photoinduced electron transfer. We constructed a novel nanosensor based upon the newly-synthesized nanomaterial and demonstrated a sensitive and selective detection for both Fe3+ ion and ascorbic acid, enabling the measurements in real clinical samples. For the first time fluorescent graphdiyne oxide quantum dots (GDYO-QDs) were prepared using a facile ultrasonic protocol and they were characterized with a range of techniques, showing a strong blue-green emission with 14.6% quantum yield. The emission is quenched efficiently by Fe3+ and recovered by ascorbic acid (AA). We have fabricated an off/on fluorescent nanosensors based on this unique property. The nanosensors are able to detect Fe3+ as low as 95 nmol L−1 with a promising dynamic range from 0.25 to 200 μmol L−1. The LOD of AA was 2.5 μmol L−1, with range of 10–500 μmol L−1. It showed a promising capability to detect Fe3+ and AA in serum samples.
  • Thumbnail Image
    ItemOpen Access
    Ultrathin graphdiyne/graphene heterostructure as a robust electrochemical sensing platform
    (American Chemical Society, 2022-09-19) Sun, Xiuchao; Duan, Menglu; Li, Rongteng; Meng, Yuan; Bai, Qiang; Wang, Lina; Liu, Manhong; Yang, Zhugen; Zhu, Zhiling; Sui, Ning
    Graphdiyne (GDY) has been considered as an appealing electrode material for electrochemical sensing because of its alkyne-rich structure and high degrees of π-conjugation, which shows great affinity to heavy metal ions and pollutant molecules via d−π and π–π interactions. However, the low surface area and poor conductivity of bulk GDY limit its electrochemical performance. Herein, a two-dimensional ultrathin GDY/graphene (GDY/G) nanostructure was synthesized and used as an electrode material for electrochemical sensing. Graphene plays the role of an epitaxy template for few-layered GDY growth and conductive layers. The formed few-layered GDY with a high surface area possesses abundant affinity sites toward heavy metal ions (Cd2+, Pb2+) and toxic molecules, for example, nitrobenzene and 4-nitrophenol, via d−π and π–π interactions, respectively. Moreover, hemin as a key part of the enzyme catalytic motif was immobilized on GDY/G via π–π interactions. The artificial enzyme mimic hemin/GDY/G-modified electrode exhibited promising ascorbic acid and uric acid detection performance with excellent sensitivity and selectivity, a good linear range, and reproducibility. More importantly, real sample detection and the feasibility of this electrochemical sensor as a wearable biosensor were demonstrated.