Microfluidic-based Bacterial Molecular Computing on a Chip

TL;DR

This paper introduces a microfluidic bacterial computing chip that uses engineered bacteria for logic operations and sensing, demonstrating experimental detection and theoretical reliability analysis for potential diagnostic applications.

Contribution

It presents a novel integrated microfluidic bacterial computing system with experimental validation and a theoretical model analyzing reliability under signal noise and delays.

Findings

Electrochemical sensors detect pH and oxygen changes from bacterial signals

The system performs AND logic and ON-OFF switching functions

Reliability is affected by signal delays and noise in the system

Abstract

Biocomputing systems based on engineered bacteria can lead to novel tools for environmental monitoring and detection of metabolic diseases. In this paper, we propose a Bacterial Molecular Computing on a Chip (BMCoC) using microfluidic and electrochemical sensing technologies. The computing can be flexibly integrated into the chip, but we focus on engineered bacterial AND Boolean logic gate and ON-OFF switch sensors that produces secondary signals to change the pH and dissolved oxygen concentrations. We present a prototype with experimental results that shows the electrochemical sensors can detect small pH and dissolved oxygen concentration changes created by the engineered bacterial populations' molecular signals. Additionally, we present a theoretical model analysis of the BMCoC computation reliability when subjected to unwanted effects, i.e., molecular signal delays and noise, and electrochemical sensors threshold settings that are based on either standard or blind detectors. Our numerical analysis found that the variations in the production delay and the molecular output signal concentration can impact on the computation reliability for the AND logic gate and ON-OFF switch. The molecular communications of synthetic engineered cells for logic gates integrated with sensing systems can lead to a new breed of biochips that can be used for numerous diagnostic applications.