Biomedical soft contact-lens sensor for in situ ocular biomonitoring of tear contents

Abstract

A soft contact-lens biosensor (SCL-biosensor) for novel non-invasive biomonitoring of tear fluids was fabricated and tested. Wearing a biosensor on eye enabled the in situ monitoring of tear contents. The biosensor has an enzyme immobilized electrode on the surface of a polydimethyl siloxane (PDMS) contact lens. The SCL-biosensor was fabricated using microfabrication techniques for functional polymers (PDMS and 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer). In investigation of in vitro characterization, the SCL-biosensor showed excellent relationship between the output current and glucose concentration from 0.03 to 5.0 mmol·L(-1), with a correlation coefficient of 0.994. The calibration range covered the reported tear glucose concentrations (0.14 mmol·L(-1)). Based on the result, ocular biomonitoring with the SCL-biosensor was carried out. The SCL-biosensor well worked both in the static state and the dynamic state. The tear glucose level of rabbit was estimated to 0.12 mmol·L(-1) at first and then the tear turnover was successfully calculated to be 29.6 ± 8.42% min(-1). The result indicated that SCL-biosensor is useful for advanced biomonitoring on eye.

Wearable Chemosensors: A Review of Recent Progress

“…However, most strip‐based sensors are fabricated on partially flexible substrates, which may cause eye irritation . In this case, soft‐contact‐lens‐based wireless sensors have been developed to solve the above limitations.…”

“…However,most strip-based sensors are fabricated on partially flexible substrates, which may cause eye irritation. [74][75][76] In this case, soft-contact-lens-based wireless sensors have been developed to solve the above limitations. Parviz's group has designed contact lens glucose sensors based on wireless electronics,w hicha re now developed by Google.…”

Cavitas Sensors: Contact Lens Type Sensors & Mouthguard Sensors

“…The peak current indicates instillation of glucose (Figure 2–). The inverse peak indicates dilution of tear glucose by instillation of physiological sodium chloride solution . The tear turnover was calculated using semi‐log regression curve.…”

Wearable Bio and Chemical Sensors

“…In recent years, significant effort has been focused on sampling and analysis of alternative body fluids, such as interstitial fluid [5], tears [6], saliva [7], and sweat [8]. The transition from blood to other body fluids provides a less invasive means of sampling, which in turn may provide a route to facilitate longer-term continuous monitoring.…”