Bacterial infections and sepsis are among the most important and common causes of death worldwide. Statistics show that more than 18 million people worldwide get sepsis annually, and 28-50% of them die. Recent studies show that timely diagnosis and appropriate antibiotic prescription are among the most important initial measures for sepsis treatment; Despite the availability of antibiotic treatments for bacterial infections, the diagnosis of these infections is often misdiagnosed or delayed. Among the common methods of identifying bacterial infections are sample culturing, PCR-based, and immunological methods; But these methods require specialized equipment and are often time-consuming and expensive, and in many cases, they do not have proper accuracy. Therefore, using new diagnostic methods such as biosensors is especially important in cases of epidemics and deprived areas. This review article examines the necessity of using biosensors to detect pathogenic bacteria. The main focus of this paper is the review of biosensors for the detection of whole bacterial cells without the need for sample processing, and the recent developments in this field are discussed.