Wireless and Flexible Optoelectronic System for In Situ Monitoring of Vaginal pH Using a Bioresorbable Fluorescence Sensor

Abstract

Herein, a miniaturized wireless sensing vaginal ring for the in situ continuous monitoring of vaginal pH and real‐time transmission of the pH data to a smartphone is reported, aimed at the diagnosis and management of bacterial vaginosis, a common condition frequently and adversely affecting women. The sensing vaginal ring consists of a bioresorbable pH fluorescence sensor placed on top of a polydimethylsiloxane ring encapsulating a miniaturized driving/readout optoelectronic circuit, data acquisition system, wireless transceiver, and power supply. The pH sensor consists of a micrometer‐thick porous silica scaffold conformably coated with a nanometer‐thick polymer multilayer stack and is intended to be replaced after 4 days. The sensor fully dissolves in biocompatible by‐products eliminating waste management issues; conversely, the ring embedding the circuit is reusable with new sensors. The pH sensor, as well as the sensing vaginal ring, show excellent performance in the continuous measurement of pH in vaginal fluid and can monitor the pH level over the physio‐pathological range of 3–7.5 with high linearity, accuracy, and reliability, transmitting the data to a smartphone in real time. The proposed technology can be immediately translated to other diseases, among which wound healing, intragastric activity, and cancer progression, where continuous monitoring of pH is required, as well as to other markers/analytes by engineering the polymer stack with suitable receptors, such as aptamers and other molecular probes.

Positively Charged Organosilanes Covalently Linked to the Silica Network as Modulating Tools for the Salinity Correction of pH Values Obtained with Colorimetric Sensor Arrays (CSAs)

“…pH is a key parameter that can be used as a probe for different phenomena like food spoilage [ 1 , 2 , 3 , 4 , 5 ], fermentation [ 6 , 7 , 8 , 9 ], ocean acidification [ 10 , 11 , 12 , 13 ], industrial processes, and so on [ 14 , 15 , 16 , 17 , 18 ]. Potentiometric determination with a glass electrode is traditionally the most important method used for pH measurement [ 19 ].…”

Ultrathin Ambipolar Polyelectrolyte Capacitors Prepared via Layer‐by‐Layer Assembling

“…Layer-by-layer (LbL) assembling of polymers, colloids, biomolecules, and cells to form multilayer thin films offers superior reliability and better control of the film properties (thickness, charge, density) when compared to other deposition techniques, such as, spin coating, drop casting, and spray coating, especially for micro-and nanostructured materials. [11] Multilayer stacks have been successfully prepared via LbL with thickness of few nm up to several μm [11,12] and employed in different research fields, including separation science, [13,14] drug delivery, [15][16][17][18] bio-medicine and -sensing, [19][20][21][22][23][24] electronics. [25] However, the use of nm-thick polyelectrolyte multilayers as dielectric material for the preparation of solid-state capacitors has been overlooked so far, and only a few studies on the dielectric behavior of polyelectrolyte stacks versus assembling condition, material, temperature, and humidity have been performed, using electrooptical methods, [26][27][28][29] impedance spectroscopy, [30,31] and DC-conductivity evaluation.…”

A Low-Power High-Sensitivity Photocurrent Sensory Circuit with Capacitive Feedback Transimpedance for Photoplethysmography Sensing

“…Thus, such optoelectronic systems combine optical and electronic components to detect, control, and manipulate light, playing a crucial role in various technological applications. One such application includes the in situ monitoring of vaginal pH using a bioresorbable fluorescence sensor [11].…”