Catechol Patterned Film Enables the Enzymatic Detection of Glucose with Cell Phone Imaging

Abstract

Biology provides an array of materials and mechanisms to create sustainable high-performance materials. Here, we prepared a polysaccharide film and patterned it with redox-active catechol moieties using a biomimetic oxidative grafting method. In this proof-of-concept study, we show that the film allows results from an enzymatic biosensing reaction to be reported through cell phone imaging for the detection of glucose in food and beverage products (glucose is a marker for high-fructose corn syrup; HFCS). This method uses glucose dehydrogenase (GDH) to confer molecular recognition, while the NADH product transfers its electrons to catechol moieties that are patterned onto a polysaccharide film. The “accumulation” of electrons by the catechol pattern can be detected because the oxidized quinone state is darker in color than the reduced catechol state. Using a commercially available cell phone imaging app, we demonstrate that HFCS-containing products can be distinguished from analogous products containing either sucrose or artificial sweeteners. Thus, we envision that this method could allow buyers or consumers to detect glucose on-site or in-home. In addition, this work further illustrates the potential of catechol-based materials for performing redox-based functions.

Orthogonal redox and optical stimuli can induce independent responses for catechol-chitosan films

“…Previous studies showed that this short-term memory can be ''read'' optically based on catechol's redox-state-dependent absorbance in the visible region (480 nm), 29 and this optical reading enables convenient cell-phone imaging to access biologically-relevant redox-based chemical information. 36 The results from the current study indicate that the long term memory (i.e., the pattern) can also be read optically and non-destructively using radiation from a different region of the electromagnetic spectrum (808 nm). In addition to reading (i.e., sensing), we envision that catechol's photothermal properties could provide a simple means for actuation just as its redox properties have been used for biological actuation.…”

Electro-Biofabrication. Coupling Electrochemical and Biomolecular Methods to Create Functional Bio-Based Hydrogels

“…In this demonstration study, Figure d shows the reducing agent, NADH, was generated enzymatically by the enzyme glucose dehydrogenase (GDH), while the transfer of electrons to the patterned dot switches the grafted moieties from their oxidized to their reduced states. Importantly, the redox state can be observed optically (e.g., by cell phone imaging) because the oxidized state is darker in color and has a higher UV–vis absorbance compared to the reduced state . From an application standpoint, this example illustrates a simple and sustainable platform for biosensing.…”

“…Importantly, the redox state can be observed optically (e.g., by cell phone imaging) because the oxidized state is darker in color and has a higher UV−vis absorbance compared to the reduced state. 145 From an application standpoint, this example illustrates a simple and sustainable platform for biosensing. From a fundamental standpoint, it is interesting to note that this molecular memory can be repeatedly switched, but these memory states are only stable for hours to days: the molecular-level reason for this instability is unclear.…”

Visualized sensing of erythritol using a simple enzyme-free catechol-based hydrogel film

“…28,30 A previous study has demonstrated that the changes of catechol's redox states can be measured alternatively by a simple cell phone imaging application method. 39 Therefore, whether the products contain only erythritol can be determined by measuring the increase of redox signals, as well as the color changes of catechol-based hydrogel lm. The results also demonstrate that the oxidized catechol-Chit 0 / agarose hydrogel lm can be used for the detection of erythritol in real samples by using a simple cell phone imaging measurement.…”