Photomicrograph of an actual multimodal bio-image sensor chip. |
The
use of sensors is important for the quantitative analyses of chemical
materials and physical phenomena, with research and development of
biosensors for observing cell function being actively pursued.
Although
there are several conventional biosensors that can be used to analyze
biological samples from one perspective, the use of biosensors for
multimodal analysis is challenging.
In
this study, Hirokazu Nakazawa and colleagues at Toyohashi University of
Technology have devised a multimodal bio-image sensor that can render
images of the 2D distribution of proton concentration (pH)
and fluorescence intensity for multimodal analyses of biochemical
objects.
A
prototype of the image sensor was fabricated at using facilities at
Toyohashi Tech’s EIIRIS research complex using a modified CMOS
fabrication process with a 5 ?m design rule. The area of each individual
sensor region was 54 ?m× 40 ?m, with 32 × 32 pixels (Fig. 1). The
bonding wires and gold electrode pads (except those in the active
region) were encapsulated to protect them from the liquid environment.
The
multimodal bio-image sensor enabled the detection and display of a wide
range of wavelengths of light at 5 frames per second, without the use
of optical filters or gratings. The researchers also used the sensor to
measure the variation of the pH distribution with time.
These
results demonstrate the potential of this imaging sensor for intra- and
extracellular measurements. The multimodal analysis approach is
effective for obtaining biochemical information in real time using
multimodal bio-image sensors with high spatial resolution.
Multimodal bio-image sensor for real-time proton and fluorescence imaging