Aggregation and Binding-Directed FRET Modulation of Conjugated Polymer Materials for Selective and Point-of-Care Monitoring of Serum Albumins

Abstract

Nonspecific interactions of conjugated polymers (CPs) with various proteins prove to be a major impediment for researchers when designing a suitable CP-based probe for the amplified and selective recognition of particular proteins in complex body fluids. Herein, a new strategy is presented for the precise and specific monitoring of clinically important serum albumin (SA) proteins at the nanomolar level using fluorescence resonance energy transfer (FRET)-modulated CP–surfactant ensembles as superior sensing materials. In brief, the newly designed color-tunable CP PF–DBT–Im undergoes intense aggregation with the surfactant sodium dodecyl sulfate (SDS), enabling drastic change in the emission color from violet to deep red due to intermolecular FRET. The emission of PF–DBT–Im/SDS ensembles then changed from deep red to magenta specifically on addition of SAs owing to the exclusive reverse FRET facilitated by synergistic effects of electrostatic interactions, hydrophobic forces, and the comparatively high intrinsic quantum yield of SAs. Interestingly, PF–DBT–Im itself could not differentiate SAs from other proteins, demonstrating the superiority of the PF–DBT–Im/SDS self-assembly over PF–DBT–Im. Finally, an affordable smartphone-integrated point-of-care (PoC) device is also fabricated as a proof-of-concept for the on-site and rapid monitoring of SAs, validating the potential of the system in long-term clinical applications.

A Smartphone Integrated Platform for Ratiometric Fluorescent Sensitive and Selective Determination of Dipicolinic Acid

“…The current fluorescence assays usually require fluorescence spectrometer and specialized researchers, which is not suitable in on-site analysis [ 32 , 33 , 34 , 35 , 36 , 37 ]. In this research, a smartphone installed a Color Picker APP is used as a signal reader to detect the DPA by integrating with the as-prepared ratiometric fluorescent sensing, Figure 4 A.…”

A Paper-Based Analytical Device Integrated with Smartphone: Fluorescent and Colorimetric Dual-Mode Detection of β-Glucosidase Activity

“…A homemade camera obscura was combined with the smartphone to obtain colorimetric images. The fabrication method of the camera obscura is similar to the previous work [ 39 , 40 ]. The structure of the camera obscura is shown in Figure 2 A: a small opening at the top of the camera obscura to expose the phone camera; honeycomb cardboard strips were affixed around the location of the smartphone to limit the location; the LED strip (12 W/m) inside the camera obscura provided a stable and uniform light source.…”

IoT-Based Healthcare-Monitoring System towards Improving Quality of Life: A Review

“…The rapid development of point-of-care (POC) sensor platforms and implantable devices with specialized functionality has been made possible by incorporating recently created materials into medical equipment [ 67 , 68 ]. A lot of work has been conducted on the clinical diagnosis of albumin-related diseases [ 69 , 70 ].…”