Finding and preserving normal parathyroid glands or localizing and removing diseased parathyroid glands are crucial steps to successful thyroid and parathyroid operations. Using near-infrared ...fluorescence detection to identify parathyroid glands during thyroid and parathyroid operations has lately gained widespread recognition, with 2 Food and Drug Administration–cleared devices currently in the market. We aim to update the endocrine surgery community on how near-infrared fluorescence detection can be most optimally used for rapid intraoperative parathyroid gland identification or preservation.
A literature review was performed using the key terms: “parathyroid,” “near infrared,” and “fluorescence” in relevant search engines. Based on the reviewed literature and expert surgeons’ opinions, recommendations were formulated for applying near-infrared fluorescence detection to identify or preserve parathyroid glands during cervical endocrine surgery.
The scope of near-infrared fluorescence detection can be broadly categorized into (1) using near-infrared auto-fluorescence to identify or locate both healthy and diseased parathyroid glands, and (2) using contrast-enhanced near-infrared fluorescence to evaluate parathyroid gland perfusion. The benefits and pitfalls for both near-infrared–based approaches are described herein.
Near-infrared fluorescence detection appears helpful for identification and likely preservation of parathyroid glands. We hope these recommendations will be valuable to the practicing endocrine surgeon as they consider incorporating these intraoperative adjuncts in their surgical practice.
A water-soluble azo functionalized oligomeric chitosan reagent (β-NAC) has been developed for the visual detection and quantification of KMnO
at micromolar concentrations. The β-NAC sensor was also ...explored as a detection probe for the spectrophotometric and spectrofluorometric detection of several metal ions and anions. The synthesized reagent was characterized by TGA-DTA-DTG analysis, DLS studies, BET analysis, and spectral analysis. The β-NAC reagent produces conspicuous colours with different concentrations and different pH values of KMnO
solution. This provides evidence for high selectivity in the visual detection of KMnO
up to the micromolar level because of its interactions in the case of KMnO
only. The colour of the β-NAC reagent after interacting with KMnO
(10
M) changes from brown to blood red. Furthermore, the β-NAC sensor was employed for the spectrophotometric detection of KMnO
. The absorption spectrum of β-NAC shows a peak at 327 nm and on interacting with KMnO
, it shows a bathochromic shift to 331 nm. The intensity of the peak at 331 nm increases as the concentration of KMnO
was increased from 1 μM to 0.01 M. The detection and quantification limits in the spectrophotometric detection of KMnO
were found to be 4.55 μM and 15.17 μM, respectively. The results of pH studies show that there is a pH effect of the KMnO
solution on KMnO
detection. The stability of the complex was determined by investigating the effect of time on the absorption intensity. In the spectrofluorometric detection, the fluorescence intensity of β-NAC at the 427 nm emission maxima was decreased on adding KMnO
solution. The fluorescence quenching increased on increasing the KMnO
concentration from 1 μM to 0.008 M. The optimum pH for fluorescence quenching was found to be 8. The detection and quantification limits in the spectrofluorometric detection of KMnO
were found to be 0.967 μM and 3.223 μM, respectively. The Stern-Volmer constant value was found to be 41 366.2 L mol
, confirming the significant complexation between KMnO
and the β-NAC reagent. Interference studies were conducted to analyse the effect of various metal ions and anions on KMnO
detection. Electrochemical studies were also performed to analyse the mechanism of complex formation.
A diverse array of small molecule-based fluorescent probes is available for many different types of biological experiments. Here we examine the history of these probes and discuss some of the most ...interesting applications. PUBLICATION ABSTRACT
In recent years, there has been an increase in pesticide use to improve crop production due to the growth of agricultural activities. Consequently, various pesticides have been present in the ...environment for an extended period of time. This review presents a general description of recent advances in the development of methods for the quantification of pesticides used in agricultural activities. Current advances focus on improving sensitivity and selectivity through the use of nanomaterials in both sensor assemblies and new biosensors. In this study, we summarize the electrochemical, optical, nano-colorimetric, piezoelectric, chemo-luminescent and fluorescent techniques related to the determination of agricultural pesticides. A brief description of each method and its applications, detection limit, purpose-which is to efficiently determine pesticides-cost and precision are considered. The main crops that are assessed in this study are bananas, although other fruits and vegetables contaminated with pesticides are also mentioned. While many studies have assessed biosensors for the determination of pesticides, the research in this area needs to be expanded to allow for a balance between agricultural activities and environmental protection.
A highly efficient fluorosensor based on ultrathin graphitic carbon nitride (g-C₃N₄) nanosheets for Cu(2+) was developed. In the absence of metal ions, the nanosheets exhibit high fluorescence; the ...strong coordination of the Lewis basic sites on them to metal ions, however, causes fluorescence quenching via photoinduced electron transfer leading to the qualitative and semiquantitative detection of metal ions. This fluorosensor exhibits high selectivity toward Cu(2+). The whole detection process can be completed within 10 min with a detection limit as low as 0.5 nM. The use of test paper enables the naked-eye detection of Cu(2+) with a detection limit of 0.1 nmol. The practical use of this sensor for Cu(2+) determination in real water samples was also demonstrated.
Due to their unique structures and multifunctionalities, two-dimensional (2D) nanomaterials have aroused increasing interest in the construction of the novel biointerfaces for biosensing ...applications. Efforts in constructing novel biointerfaces led to exploit the more versatile and tunable graphene-like 2D nanomaterials (e.g. graphitic carbon nitride, boron nitride, transition metal dichalcogenides, and transition metal oxides) with various structural and compositional characteristics. This review highlights recent efforts in the design of graphene-like 2D nanomaterials and their derived biointerfaces and exploitation of their research on fluorescent sensors and a series of electrochemical sensors, including amperometric, electrochemiluminescence, photoelectrochemical and field-effect transistor sensors. Finally, we discuss some critical challenges and future perspectives in this field.
•Graphene-like 2D nanomaterials are promising in designing functional biointerfaces.•We review graphene-like 2D nanomaterial-based electrochemical sensors.•We review graphene-like 2D nanomaterial-based fluorescent sensors.•Rational design of novel graphene-like nanomaterial-based biointerfaces is summarized.
As analytical chemists, the highest resolution measurement one can make is at the single molecule level; it just does not get any better than that. To determine the concentration of a molecule in ...solution, the best way is to count the number of molecules in a given volume. As long as the volume contains a statistically large enough number of molecules and is above the Poisson noise limit, molecular counting is the most accurate way to make a measurement. Molecular counting is the method of the future and is beginning to be performed today.
The determination of the fluorescence quantum yields (QY, Φ(f)) of a series of fluorescent dyes that span the absorption/excitation and emission ranges of 520-900 and 600-1000 nm is reported. The ...dyes encompass commercially available rhodamine 101 (Rh-101, Φ(f) = 0.913), cresyl violet (0.578), oxazine 170 (0.579), oxazine 1 (0.141), cryptocyanine (0.012), HITCI (0.283), IR-125 (0.132), IR-140 (0.167), and four noncommercial cyanine dyes with specific spectroscopic features, all of them in dilute ethanol solution. The QYs have been measured relative to the National Institute of Standards and Technology's standard reference material (SRM) 936a (quinine sulfate, QS) on a traceably characterized fluorometer, employing a chain of transfer standard dyes that include coumarin 102 (Φ(f) = 0.764), coumarin 153 (0.544), and DCM (0.435) as links between QS and Rh-101. The QY of Rh-101 has also been verified in direct measurements against QS using two approaches that rely only on instrument correction. In addition, the effects of temperature and the presence of oxygen on the fluorescence quantum yield of Rh-101 have been assessed.
High-yield preparation of ultrathin two-dimensional (2D) nanosheets is of great importance for the further exploration of their unique properties and promising applications. Herein, for the first ...time, the high-yield and scalable production of ultrathin 2D ternary chalcogenide nanosheets, including Ta2NiS5 and Ta2NiSe5, in solution is achieved by exfoliating their layered microflakes. The size of resulting Ta2NiS5 and Ta2NiS5 nanosheets ranges from tens of nanometers to few micrometers. Importantly, the production yield of single-layer Ta2NiS5 nanosheets is very high, ca. 86%. As a proof-of-concept application, the single-layer Ta2NiS5 is used as a novel fluorescence sensing platform for the detection of DNA with excellent selectivity and high sensitivity (with detection limit of 50 pM). These solution-processable, high-yield, large-amount ternary chalcogenide nanosheets may also have potential applications in electrocatalysis, supercapacitors, and electronic devices.
In vitro biosensors have been an integral component for early diagnosis of cancer in the clinic. Among them, no-wash biosensors, which only depend on the simple mixing of the signal generating probes ...and the sample solution without additional washing and separation steps, have been found to be particularly attractive. The outstanding advantages of facile, convenient, and rapid response of no-wash biosensors are especially suitable for point-of-care testing (POCT). One fast-growing field of no-wash biosensor design involves the usage of nanomaterials as signal amplification carriers or direct signal generating elements. The analytical capacity of no-wash biosensors with respect to sensitivity or limit of detection, specificity, stability, and multiplexing detection capacity is largely improved because of their large surface area, excellent optical, electrical, catalytic, and magnetic properties. This review provides a comprehensive overview of various nanomaterial-enhanced no-wash biosensing technologies and focuses on the analysis of the underlying mechanism of these technologies applied for the early detection of cancer biomarkers ranging from small molecules to proteins, and even whole cancerous cells. Representative examples are selected to demonstrate the proof-of-concept with promising applications for in vitro diagnostics of cancer. Finally, a brief discussion of common unresolved issues and a perspective outlook on the field are provided.
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