Colorimetric and Fluorometric Profiling of Advanced Glycation End Products

Abstract

Profiling of advanced glycation end products (AGEs) is an emerging area of clinical significance for disease diagnosis and prognosis. Typically, concentrations of AGEs are estimated in laboratories by trained personnel using sophisticated equipment. Herein, a facile approach for colorimetric and fluorometric profiling of AGEs is reported for rapid and on-site analysis. The concentrations of AGE levels in plasma are estimated via changes in optical properties of polythiophenes (PTs) upon interaction with aptamers (Apts) in the presence and in the absence of AGEs. To validate the proposed approach, glyceraldehyde-derived AGEs (AGE class 1 [AGE1]), the biomarker associated with cardiovascular diseases and diabetes, are used as a model system. Colorimetric analysis yielded linear responses for AGE1 for clinically relevant concentration ranges between 1.5 and 300 μg/mL with a limit of detection (LOD) of ∼1.3 μg/mL. Subsequently, an approach utilizing PTs with four different pendant groups in conjunction with four different Apts is demonstrated for qualitative colorimetric profiling and for quantitative fluorometric profiling of up to four AGEs in clinical matrices. Principal component analysis (PCA) of fluorometric responses of AGE-spiked samples yielded distinct responses for the different AGEs tested. Thus, the proposed approach ascertains rapid profiling of spiked AGEs in plasma samples without the requirement of preanalytical processing and advanced instrumentation, thereby facilitating on-site diagnosis.

Ultrasensitive and On-Site Detection of Carbaryl Pesticides via Dual-Mode Nanosensors Utilizing Portable Devices

“…Figure E shows the FT-IR spectra of AuNPs and AuNPs + carbaryl, respectively. The FT-IR spectra show that the AuNPs mainly display two characteristic peaks, including 1639 and 3450 cm –1 , belonging to the N–H stretching vibration, indicating that the as-synthesized AuNPs successfully modified with the amino groups . As shown in Figure E, the stretching vibration absorption band of the free amide groups in carbaryl appears at 3306 cm –1 compared to AuNPs and AuNPs + carbaryl.…”

“…The FT-IR spectra show that the AuNPs mainly display two characteristic peaks, including 1639 and 3450 cm −1 , belonging to the N−H stretching vibration, indicating that the as-synthesized AuNPs successfully modified with the amino groups. 33 As shown in Figure 1E, the stretching vibration absorption band of the free amide groups in carbaryl appears at 3306 cm −1 compared to AuNPs and AuNPs + carbaryl. The absorption bands of amide groups in AuNPs + carbaryl were found at 3450 cm −1 , suggesting the electrostatic interaction between AuNPs and the acetamide groups in carbaryl.…”

L‐Lysine Ameliorates Diabetic Nephropathy in Rats with Streptozotocin‐Induced Diabetes Mellitus

“…Accordingly, serum samples were diluted 1 : 50 using 0.1 sodium phosphate buffer (pH: 7.4) and fluorescence intensity was measured at an excitation wavelength of 380 nm and a maximum emission of 440 nm using a spectrophotometer (PerkinElmer/LS55). Results were reported as the percentage of fluorescence emission (F%) [ 30 ].…”

Methylglyoxal and Its Adducts: Induction, Repair, and Association with Disease

“…Initial approaches involved the use of skin autofluorescence, a noninvasive technique that measures tissue accumulation of MG-AGEs, a technique that has proven useful in predicting development of cardiovascular disease, microvascular complications, or kidney transplant rejection . In contrast, newer methods use mass spectrometry or colorimetric and fluorometric profiling of MG-AGEs to allow for rapid measurement and analysis of clinically relevant concentrations. ,− …”

“… 279 In contrast, newer methods use mass spectrometry or colorimetric and fluorometric profiling of MG-AGEs to allow for rapid measurement and analysis of clinically relevant concentrations. 278 , 280 − 283 …”